{"id":74,"date":"2017-05-26T15:06:48","date_gmt":"2017-05-26T14:06:48","guid":{"rendered":"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/?page_id=74"},"modified":"2020-07-17T15:39:41","modified_gmt":"2020-07-17T14:39:41","slug":"17th-c-frame","status":"publish","type":"page","link":"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/objects\/17th-c-frame\/","title":{"rendered":"A Baroque Pietre Dure Frame"},"content":{"rendered":"<div class=\"mceTemp\">\n<p>Natasha Gertler guides us around the many\u00a0 minerals that decorate a lavish 16th century portable altar. Natasha researched and produced this project during her MSc in Science Communication at Imperial College, London.\u00a0<\/p>\n\n[aesop_parallax  height=&#8221;2000&#8243; img=&#8221;https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/11\/frame2.jpg&#8221; parallaxbg=&#8221;fixed&#8221; parallaxspeed=&#8221;6&#8243; caption=&#8221;Anonymous maker, Portable altar frame, ebony with pietre dure decoration, first half of 17th century, 61 x 35 x 10 cm, \u00a9 The Samuel Courtauld Trust, The Courtauld Gallery, London, P.1978.PG.3&#8243; captionposition=&#8221;bottom-left&#8221; lightbox=&#8221;on&#8221; floater=&#8221;off&#8221; floaterposition=&#8221;left&#8221; floaterdirection=&#8221;none&#8221; overlay_revealfx=&#8221;off&#8221;]\n\n<p>In Pieter Aertsen\u2019s (1508\u201375) panel from 1530, Christ drops to his knees in agony, the weight of his cross too much to bear. When the artist painted this heart-wrenching artwork, he could hardly have known that centuries later, it would be placed in a frame that threatens to steal the show! This Roman baroque frame is a magnificent object in its own right. Here is the place to learn more about its meticulous craftsmanship and how one goes about identifying its multitude of semi-precious stones. We will discover which characteristics to look out for in lapis lazuli, amethyst, agate and Sicilian jasper.<\/p>\n\n<p><span style=\"font-size: 18pt\"><strong>Pietre Dure Decoration<\/strong><\/span><\/p>\n<p>This frame is typical of the richly decorated portable altars of the baroque period, which were commissioned by wealthy individuals for their private chapels. It was only in the late 1960s that the collector Count Antoine Seilern (1901\u201378) acquired it to serve as a frame for Aertsen\u2019s double-sided painting. As well as Christ carrying the cross, the panel depicts the Annunciation. The frame is elaborately inlaid with an arrangement of coloured and patterned stones, using an Italian technique known as <em>pietre dure<\/em>. Translated as \u2018hard rock\u2019 in English, this practice originated in the 16<sup>th<\/sup>-century Florentine workshops of the Medici and refers to the inlaying of fitted, polished stones to create decorative compositions.<\/p>\n<p>A video of the recreation of a <em>pietre dure<\/em> panel from a 17<sup>th<\/sup> century cabinet can be seen\u00a0here:<\/p>\n\n<p><iframe loading=\"lazy\" title=\"Making a pietre dura panel\" width=\"1000\" height=\"750\" src=\"https:\/\/www.youtube.com\/embed\/RoP7XCnsfbY?feature=oembed&#038;enablejsapi=1&#038;origin=https:\/\/sites.courtauld.ac.uk\" frameborder=\"0\" allow=\"accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture\" allowfullscreen><\/iframe><\/p>\n[Video courtesy of the Victoria &amp; Albert Museum. <a href=\"https:\/\/www.youtube.com\/watch?v=RoP7XCnsfbY\">View on YouTube<\/a>]\n\n<p><em>Pietre dure<\/em> is the beautiful result of the interplay of man and nature. Through cutting, polishing and delicate arrangement, the true beauty of nature\u2019s wonders are revealed. Sometimes even coloured materials were placed behind translucent stones in order to enhance their sheen. This is probably the case for the lower wine-coloured band, where amethyst, a translucent mineral, seems to have been backed with a red material, producing a reddish-orange glow when illuminated:<\/p>\n<figure id=\"attachment_31\" aria-describedby=\"caption-attachment-31\" style=\"width: 408px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-31\" src=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/Sicilian-Jasper-red-showing-gold-under-the-microscope-1024x768.jpg\" alt=\"\" width=\"408\" height=\"307\" srcset=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/Sicilian-Jasper-red-showing-gold-under-the-microscope-1024x768.jpg 1024w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/Sicilian-Jasper-red-showing-gold-under-the-microscope-300x225.jpg 300w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/Sicilian-Jasper-red-showing-gold-under-the-microscope-768x576.jpg 768w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/Sicilian-Jasper-red-showing-gold-under-the-microscope-600x450.jpg 600w\" sizes=\"auto, (max-width: 408px) 100vw, 408px\" \/><figcaption id=\"caption-attachment-31\" class=\"wp-caption-text\">Backed amethyst inlay &#8211; illuminated and viewed through a microscope<\/figcaption><\/figure>\n<p>At first, we thought that this backing could be a red metallic foil but it is in fact more likely to be a red resin, based on the very recent discovery of resin behind some of the amethyst pieces in the J. Paul Getty Museum\u2019s extraordinary Borghese-Windsor cabinet, as shown below:<\/p>\n<p><div id=\"fb-root\"><\/div>\n<p><script async=\"1\" defer=\"1\" crossorigin=\"anonymous\" src=\"https:\/\/connect.facebook.net\/en_US\/sdk.js#xfbml=1&amp;version=v7.0\" nonce=\"Uur4JTkm\"><\/script><\/p>\n<div class=\"fb-video\" data-href=\"https:\/\/www.facebook.com\/gettymuseum\/videos\/10155288708925097\/\" data-width=\"1000\">\n<blockquote cite=\"https:\/\/www.facebook.com\/gettymuseum\/videos\/10155288708925097\/\" class=\"fb-xfbml-parse-ignore\"><p><a href=\"https:\/\/www.facebook.com\/gettymuseum\/videos\/10155288708925097\/\">The Borghese-Windsor Cabinet<\/a><\/p>\n<p>The Borghese-Windsor Cabinet goes on view today at the Getty Center. Anne-Lise Desmas, curator and department head sculpture and decorative arts, invites you to take a closer look at this magnificent work of furniture, sculpture and stone inlay (pietre dure) made in Rome about 1620 for Pope Paul V and later acquired by King George IV of England. The cabinet is now on view in the East pavilion at the Getty Center. Learn more about this important acquisition and plan your visit: http:\/\/bit.ly\/2s4LLgV<\/p>\n<p>Posted by <a href=\"https:\/\/www.facebook.com\/gettymuseum\/\">Getty<\/a> on Tuesday, June 13, 2017<\/p><\/blockquote>\n<\/div>\n[Video courtesy of the J. Paul Getty Museum]\n\n<p>Of striking resemblance to the Courtauld&#8217;s frame, in both their design and arrangement\u00a0of the stones, are two\u00a0portable altars of similar sizes in the collections of the Palazzo Pallavicini in Rome and the Victoria and Albert Museum in London (V&amp;A). All of\u00a0these frames are made in Rome and dated to the first half of the 17th century. Despite differences in their details, and the more elaborate decoration and richer appearance of the Pallavicini example, the\u00a0<em>pietre dure<\/em> inlays are very similar. We can see a prominent use of lapis lazuli, amethyst, agate and some of the same varieties of Sicilian jaspers. \u00a0It is intriguing to note that both the V&amp;A and the Courtauld frames seem to exhibit the same amethyst inlay probably backed with a red substance (resin?), as mentioned above.<\/p>\n<div id='gallery-1' class='gallery galleryid-74 gallery-columns-2 gallery-size-large'><figure class='gallery-item'>\n\t\t\t<div class='gallery-icon portrait'>\n\t\t\t\t<a href='https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/objects\/17th-c-frame\/bringing-it-all-together\/pallavicini-rome-frame-imperial-2017\/'><img loading=\"lazy\" decoding=\"async\" width=\"463\" height=\"749\" src=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/pallavicini-rome-frame-imperial-2017.jpg\" class=\"attachment-large size-large\" alt=\"Portable altar\" aria-describedby=\"gallery-1-145\" srcset=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/pallavicini-rome-frame-imperial-2017.jpg 463w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/pallavicini-rome-frame-imperial-2017-185x300.jpg 185w\" sizes=\"auto, (max-width: 463px) 100vw, 463px\" \/><\/a>\n\t\t\t<\/div>\n\t\t\t\t<figcaption class='wp-caption-text gallery-caption' id='gallery-1-145'>\n\t\t\t\tPortable altar<br \/>\r\nRome, first half of the 17<sup>th<\/sup> century, ebony with pietre dure decoration of lapis lazuli, amethyst, agate and Sicilian jasper, 62 x 35 x 9 cm, Adoration of the Magi below two putti, oil on amethyst, Palazzo Pallavicini, Rome\n\t\t\t\t<\/figcaption><\/figure><figure class='gallery-item'>\n\t\t\t<div class='gallery-icon portrait'>\n\t\t\t\t<a href='https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/objects\/17th-c-frame\/bringing-it-all-together\/v-and-a-frame-imperial-2017\/'><img loading=\"lazy\" decoding=\"async\" width=\"634\" height=\"1024\" src=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/v-and-a-frame-imperial-2017-634x1024.jpg\" class=\"attachment-large size-large\" alt=\"House altar\" aria-describedby=\"gallery-1-146\" srcset=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/v-and-a-frame-imperial-2017-634x1024.jpg 634w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/v-and-a-frame-imperial-2017-186x300.jpg 186w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/v-and-a-frame-imperial-2017-768x1241.jpg 768w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/v-and-a-frame-imperial-2017-600x969.jpg 600w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/v-and-a-frame-imperial-2017.jpg 1524w\" sizes=\"auto, (max-width: 634px) 100vw, 634px\" \/><\/a>\n\t\t\t<\/div>\n\t\t\t\t<figcaption class='wp-caption-text gallery-caption' id='gallery-1-146'>\n\t\t\t\tHouse altar<br \/>\r\nRome, first half of the 17<sup>th<\/sup> century, ebony with pietre dure decoration of lapis lazuli, amethyst, agate, Sicilian jasper and tortoiseshell, 50 x 31 x 7 cm, The Flight into Egypt, oil on lapis lazuli,\r\nVictoria and Albert Museum, London, 1556-1856\n\t\t\t\t<\/figcaption><\/figure><figure class='gallery-item'>\n\t\t\t<div class='gallery-icon portrait'>\n\t\t\t\t<a href='https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/objects\/17th-c-frame\/frame-2000x3232\/'><img loading=\"lazy\" decoding=\"async\" width=\"634\" height=\"1024\" src=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/Frame-2000x3232-634x1024.jpg\" class=\"attachment-large size-large\" alt=\"Portable altar\" aria-describedby=\"gallery-1-80\" srcset=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/Frame-2000x3232-634x1024.jpg 634w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/Frame-2000x3232-186x300.jpg 186w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/Frame-2000x3232-768x1241.jpg 768w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/Frame-2000x3232-600x970.jpg 600w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/Frame-2000x3232.jpg 2000w\" sizes=\"auto, (max-width: 634px) 100vw, 634px\" \/><\/a>\n\t\t\t<\/div>\n\t\t\t\t<figcaption class='wp-caption-text gallery-caption' id='gallery-1-80'>\n\t\t\t\tFrame (originally a portable altar?)\r\nRome, first half of the 17th century, ebony with pietre dure decoration, 61 x 35 x 10 cm, double-sided painting attributed to Pieter Aertsen (1508-1575), Christ Bearing the Cross (front) and the Annunciation (reverse), oil on panel, The Samuel Courtauld Trust, The Courtauld Gallery, London, P.1978.PG.3\n\t\t\t\t<\/figcaption><\/figure><figure class='gallery-item'>\n\t\t\t<div class='gallery-icon portrait'>\n\t\t\t\t<a href='https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/objects\/17th-c-frame\/bringing-it-all-together\/p-1978-pg-3_verso-imperial-2017-b\/'><img loading=\"lazy\" decoding=\"async\" width=\"634\" height=\"1024\" src=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/P.1978.pg_.3_verso-imperial-2017-b-634x1024.jpg\" class=\"attachment-large size-large\" alt=\"House altar\" srcset=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/P.1978.pg_.3_verso-imperial-2017-b-634x1024.jpg 634w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/P.1978.pg_.3_verso-imperial-2017-b-186x300.jpg 186w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/P.1978.pg_.3_verso-imperial-2017-b-768x1241.jpg 768w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/P.1978.pg_.3_verso-imperial-2017-b-600x970.jpg 600w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/P.1978.pg_.3_verso-imperial-2017-b.jpg 1847w\" sizes=\"auto, (max-width: 634px) 100vw, 634px\" \/><\/a>\n\t\t\t<\/div><\/figure>\n\t\t<\/div>\n\n\n\n<p><span style=\"font-size: 18pt\"><strong>Rocks and Minerals<\/strong><\/span><\/p>\n<p>A <strong>rock<\/strong> is a natural composition of one or more minerals. A <strong>mineral<\/strong> is a naturally occurring, inorganic solid with a defined chemical composition and an ordered atomic structure. For example, quartz is a mineral with a chemical composition of silicon dioxide, SiO<sub>2<\/sub>, with the silicon (yellow) and oxygen (red) atoms ordered in a regular arrangement as shown below.<\/p>\n<figure id=\"attachment_35\" aria-describedby=\"caption-attachment-35\" style=\"width: 408px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-35 \" src=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/Crystalline-structure-of-quartz-reduced-1024x1024.jpg\" alt=\"\" width=\"408\" height=\"408\" srcset=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/Crystalline-structure-of-quartz-reduced-1024x1024.jpg 1024w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/Crystalline-structure-of-quartz-reduced-150x150.jpg 150w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/Crystalline-structure-of-quartz-reduced-300x300.jpg 300w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/Crystalline-structure-of-quartz-reduced-768x768.jpg 768w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/Crystalline-structure-of-quartz-reduced-800x800.jpg 800w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/Crystalline-structure-of-quartz-reduced-60x60.jpg 60w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/Crystalline-structure-of-quartz-reduced-600x600.jpg 600w\" sizes=\"auto, (max-width: 408px) 100vw, 408px\" \/><figcaption id=\"caption-attachment-35\" class=\"wp-caption-text\">Crystalline structure of quartz (Shutterstock illustration ID: 124138606)<\/figcaption><\/figure>\n<p>The term <strong>stone<\/strong> refers to a rock or mineral that has been subjected to human handling or use, such as in the technique of <em>pietre dure<\/em>, or more generally the inlay of hard stones into decorative compositions.\u00a0The stones in the Courtauld\u2019s baroque <em>pietre dure<\/em>\u00a0frame are all the product of a geological process known as <strong>mineralization<\/strong>: the infiltration of silica-rich fluids through the cracks, fissures and cavities in solid rock. When cooled, these fluids solidify, precipitating crystals.<\/p>\n<p>In order to accurately identify a stone, it is necessary to identify its constituent minerals. Amongst the physical properties used to distinguish minerals, only several can be observed non-intrusively: colour, lustre and transparency (see below). Other mineral properties include hardness, cleavage, fracture and streak, although these can only be investigated using intrusive techniques.<\/p>\n<p><strong>Colour <\/strong><\/p>\n<p>The mineral lazurite is always blue. However, some minerals can form in a variety of colours due to the inclusion of different chemical impurities, known as trace elements, in their atomic structure. For example, pure quartz or rock crystal is colourless, but it can also appear pink or red with the inclusion of iron in different states of oxidation. One such case is purple amethyst, which includes traces of Fe<sup>3+<\/sup>.<\/p>\n<p><strong>Lustre <\/strong><\/p>\n<p>The word \u2018lustre\u2019 describes the way in which light reflects off the surface of the sample of mineral or rock. This is a visual scale, whereby the surfaces of minerals can be described using terms such as \u2018metallic\u2019, \u2018vitreous\u2019 (glass-like), \u2018waxy\u2019, \u2018dull\u2019 or \u2018adamantine\u2019 (diamond-like).<\/p>\n<p><strong>Transparency <\/strong><\/p>\n<p>The transparency of a mineral describes the amount of light able to pass through the sample. It is classified into three categories: \u2018opaque\u2019<em>,<\/em> which allows no light through;\u00a0\u2018translucent\u2019, which allows some light through; and \u2018transparent\u2019,<em>\u00a0<\/em>which allows all of the light through.<\/p>\n\n\n<p><span style=\"font-size: 18pt\"><strong>Decorative Stone Identification<\/strong><\/span><\/p>\n<p>Identifying decorative stones, such as those used in The Courtauld Gallery\u2019s <em>pietre dure<\/em> frame, may be one of those instances where scientific investigation is inappropriate. While geologists use destructive analytical techniques to accurately identify rocks and minerals\u00a0from the field \u2014 smashing them open or finely slicing them to view under a microscope \u2014 these methods are not an option when considering valuable and historically important objects from a museum collection.<\/p>\n<p>Moreover, even some non-intrusive techniques are not particularly useful for decorative stone identification. Most analytical techniques, such as X-Ray Fluorescence (XRF) and Raman spectroscopy, provide information on either crystal structure or chemical composition. However, many materials that look very different may have essentially the same chemistry. For example, glass, quartz, amethyst, agate and jasper are all composed of silica (SiO<sub>2<\/sub>). Therefore, chemical techniques can tell us what a stone is, but can rarely tell us where it came from.<\/p>\n<p>These limitations mean that decorative stones are usually identified by a combination of observation, connoisseurship and comparison with other stones of known provenance. An excellent resource for identifying decorative stones is the extensive <a href=\"http:\/\/www.oum.ox.ac.uk\/corsi\/stones\/browse\">Corsi collection<\/a>. Composed of\u00a0exactly 1000 polished stone slabs of uniform shape and size (145 x 73 x 40 mm), the collection\u00a0was established by the Roman lawyer Faustino Corsi (1771\u20131846) by the first quarter of the 19th century and is now housed in the Oxford University Museum of Natural History.\u00a0<\/p>\n<div id='gallery-2' class='gallery galleryid-74 gallery-columns-3 gallery-size-full'><figure class='gallery-item'>\n\t\t\t<div class='gallery-icon portrait'>\n\t\t\t\t<a href='https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/Frame-2000x3232.jpg'><img loading=\"lazy\" decoding=\"async\" width=\"2000\" height=\"3232\" src=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/Frame-2000x3232.jpg\" class=\"attachment-full size-full\" alt=\"Portable altar\" aria-describedby=\"gallery-2-80\" srcset=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/Frame-2000x3232.jpg 2000w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/Frame-2000x3232-186x300.jpg 186w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/Frame-2000x3232-768x1241.jpg 768w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/Frame-2000x3232-634x1024.jpg 634w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/Frame-2000x3232-600x970.jpg 600w\" sizes=\"auto, (max-width: 2000px) 100vw, 2000px\" \/><\/a>\n\t\t\t<\/div>\n\t\t\t\t<figcaption class='wp-caption-text gallery-caption' id='gallery-2-80'>\n\t\t\t\tFrame (originally a portable altar?)\r\nRome, first half of the 17th century, ebony with pietre dure decoration, 61 x 35 x 10 cm, double-sided painting attributed to Pieter Aertsen (1508-1575), Christ Bearing the Cross (front) and the Annunciation (reverse), oil on panel, The Samuel Courtauld Trust, The Courtauld Gallery, London, P.1978.PG.3\n\t\t\t\t<\/figcaption><\/figure><figure class='gallery-item'>\n\t\t\t<div class='gallery-icon portrait'>\n\t\t\t\t<a href='https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/frame-schematic2.jpg'><img loading=\"lazy\" decoding=\"async\" width=\"1217\" height=\"2000\" src=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/frame-schematic2.jpg\" class=\"attachment-full size-full\" alt=\"Line drawing showing the different types of stones present in the frame.\" aria-describedby=\"gallery-2-173\" srcset=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/frame-schematic2.jpg 1217w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/frame-schematic2-183x300.jpg 183w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/frame-schematic2-768x1262.jpg 768w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/frame-schematic2-623x1024.jpg 623w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/frame-schematic2-600x986.jpg 600w\" sizes=\"auto, (max-width: 1217px) 100vw, 1217px\" \/><\/a>\n\t\t\t<\/div>\n\t\t\t\t<figcaption class='wp-caption-text gallery-caption' id='gallery-2-173'>\n\t\t\t\tLine drawing showing the different types of stones present in the frame. (A) Lapis lazuli (B) Amethyst (C) Agate (D) Sicilian jasper\n\t\t\t\t<\/figcaption><\/figure>\n\t\t<\/div>\n\n<h2><span style=\"font-size: 18pt\"><strong>Lapis Lazuli<\/strong><\/span><\/h2>\n\n<p>Lapis is the Latin word for \u2018stone\u2019. Lazuli originates from the Persian word <em>lazhuward<\/em> meaning \u2018blue\u2019, and the Arabic word <em>lazaward<\/em> meaning \u2018sky\u2019. This rock is composed primarily of the minerals lazurite, pyrite and calcite. Pyrite has a metallic lustre, whereas calcite and lazurite have sub-vitreous lustres. All three minerals are opaque. Lazurite gives lapis lazuli its characteristic and highly prized blue colour, pyrite appears as golden flecks, often referred to as \u2018the stars in the sky\u2019, and calcite is present as white veins running throughout the rock. The more calcite in the chemical composition, the whiter the rock and the less valuable it is.<\/p>\n<p>The highest-quality lapis lazuli is most commonly mined from Sar-e-Sang in the Badakhshan region of northern Afghanistan. It has been sourced there for over 6000 years. Nowadays, lapis lazuli quarries can also be found in the banks of Russia\u2019s Slyudyanka and Malaya Bystraya rivers, as well as Lake Baikal.<\/p>\n<p>Due to its intense blue colour, lapis lazuli has been extensively used for decorative purposes since antiquity. For example, the ancient Egyptians used it to embellish sacred objects, and the Babylonians shaped it into beads for adornments.<\/p>\n<p><strong>Lapis Lazuli for Pigment<\/strong><\/p>\n<p>Lapis lazuli was also widely used in Medieval and Renaissance paintings as a deep blue pigment known as ultramarine. For example, it was used to paint the blue clothing in Ortolano\u2019s (fl. 1500\u2013after 1527) <em>Woman Taken in Adultery<\/em>,\u00a0of 1524\u201327, which is displayed near to the display case for our frame in The Courtauld Gallery.<\/p>\n\n<figure id=\"attachment_29\" aria-describedby=\"caption-attachment-29\" style=\"width: 700px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-29\" src=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/Ortolanos-Woman-Taken-in-Adultery.jpg\" alt=\"\" width=\"700\" height=\"580\" srcset=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/Ortolanos-Woman-Taken-in-Adultery.jpg 700w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/Ortolanos-Woman-Taken-in-Adultery-300x249.jpg 300w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/Ortolanos-Woman-Taken-in-Adultery-600x497.jpg 600w\" sizes=\"auto, (max-width: 700px) 100vw, 700px\" \/><figcaption id=\"caption-attachment-29\" class=\"wp-caption-text\">Ortolano (active about 1500-1527), \u2018Woman Taken in Adultery\u2019, 1524-27, oil on panel, 71.6 x 81.3 cm.\u00a0\u00a9 The Samuel Courtauld Trust, The Courtauld Gallery, London. P.1947.LF.301<\/figcaption><\/figure>\n<p>In his celebrated craftsman\u2019s handbook, <em>Il Libro dell&#8217;Arte<\/em>,\u00a0Cennino Cennini (1360\u20131427) describes many different methods and techniques used in painting and decorating surfaces. Included in this manual\u00a0is a detailed explanation of the long and arduous process required to prepare ultramarine pigment from rough lapis lazuli rock. Cennini\u2019s admiration for the hue is evident in his claim that &#8220;ultramarine blue is a colour illustrious, beautiful, and most perfect, beyond all other colours; one could not say anything about it, or do anything with it, that its quality would not still surpass.&#8221;<\/p>\n<p>A full version of this account, entitled <em>On the Character of Ultramarine Blue, and How to Make it<\/em>,\u00a0can be found <a href=\"http:\/\/www.noteaccess.com\/Texts\/Cennini\/2a.htm\">here<\/a>.<\/p>\n<h2>\u00a0<\/h2>\n<h2><strong>Agate<\/strong><\/h2>\n<p>Agate is a variety of quartz, characterised by its concentrically banded appearance. Banded agate forms by the permeation and build-up of layers of silica in cavities within rocks. It is frequently found in <a href=\"https:\/\/www.britannica.com\/science\/basalt\">basalts<\/a>. The silica solution separates into layers, some containing water and others without, resulting in the distinctive concentric bands.<\/p>\n<p>Agates come in a wide variety of colour combinations, almost all of which are a result of the inclusion of iron oxides in its chemical composition. Agate can range from opaque to transparent and has a vitreous lustre. Several varieties were used as inlays on The Courtauld&#8217;s opulent frame, as seen in these images.<\/p>\n\n<div id='gallery-3' class='gallery galleryid-74 gallery-columns-2 gallery-size-full'><figure class='gallery-item'>\n\t\t\t<div class='gallery-icon landscape'>\n\t\t\t\t<img loading=\"lazy\" decoding=\"async\" width=\"328\" height=\"304\" src=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/agate4-e1496926740280.jpg\" class=\"attachment-full size-full\" alt=\"agate close up\" srcset=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/agate4-e1496926740280.jpg 328w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/agate4-e1496926740280-300x278.jpg 300w\" sizes=\"auto, (max-width: 328px) 100vw, 328px\" \/>\n\t\t\t<\/div><\/figure><figure class='gallery-item'>\n\t\t\t<div class='gallery-icon landscape'>\n\t\t\t\t<img loading=\"lazy\" decoding=\"async\" width=\"354\" height=\"304\" src=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/agate-new.jpg\" class=\"attachment-full size-full\" alt=\"agate close up\" srcset=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/agate-new.jpg 354w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/agate-new-300x258.jpg 300w\" sizes=\"auto, (max-width: 354px) 100vw, 354px\" \/>\n\t\t\t<\/div><\/figure><figure class='gallery-item'>\n\t\t\t<div class='gallery-icon landscape'>\n\t\t\t\t<img loading=\"lazy\" decoding=\"async\" width=\"673\" height=\"214\" src=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/agate3.jpg\" class=\"attachment-full size-full\" alt=\"agate close up\" srcset=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/agate3.jpg 673w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/agate3-300x95.jpg 300w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/agate3-600x191.jpg 600w\" sizes=\"auto, (max-width: 673px) 100vw, 673px\" \/>\n\t\t\t<\/div><\/figure><figure class='gallery-item'>\n\t\t\t<div class='gallery-icon landscape'>\n\t\t\t\t<img loading=\"lazy\" decoding=\"async\" width=\"695\" height=\"222\" src=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/agate2-1.jpg\" class=\"attachment-full size-full\" alt=\"agate close up\" srcset=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/agate2-1.jpg 695w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/agate2-1-300x96.jpg 300w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/agate2-1-600x192.jpg 600w\" sizes=\"auto, (max-width: 695px) 100vw, 695px\" \/>\n\t\t\t<\/div><\/figure>\n\t\t<\/div>\n\n\n<p>Whilst agate is now found commonly worldwide, Germany has long been one of the best-known historic sources of agate with over 50 quarries in and around the famous lapidary (stone-cutting) workshop of Idar-Oberstein. Situated on either side of the fast-moving Nahe river, Idar-Oberstein became one of the main stone-cutting centres in the late 15<sup>th<\/sup> century, since the high-powered water provided enough energy to turn the large sandstone grinding wheels that were up to 3.3m in diameter.<\/p>\n<p>Agate has been valued for its hardness as well as its decorative properties, with uses including polishing gold. Small hand tools with differently shaped agate tips have been used for burnishing gold leaf for centuries up until the present day.<\/p>\n<h2><span style=\"font-size: 18pt\"><strong>Amethyst<\/strong><\/span><\/h2>\n\n<p>Amethyst is a purple variety of quartz. Its regal colouring appears in a range of hues, varying from light lilac to deep indigo depending on the abundance of iron in its chemical composition. It has a vitreous lustre and is translucent.<\/p>\n<p>Amethyst often grows along the inner walls of hollow igneous rocks, known as vesicles. Vesicles are produced by bubbles of gas in magma or lava creating cavities in the rock when solidified.\u00a0Small cracks in these rocks allow for liquid silica to seep in, which then precipitates crystals of amethyst.<\/p>\n<p>During the 17<sup>th<\/sup> century, when this frame was made, amethyst was found in a multitude of European sources, particularly in Bohemia and the Black Forest. It then would have been sold to the famous lapidary workshops of Idar-Oberstein for cutting and polishing.<\/p>\n<p>Nowadays, the largest commercial sources of amethyst are Brazil, Uruguay, Siberia and North America. The largest amethyst geode (a rock cavity lined with crystals or other mineral matter) in the world is the<em> Empress of Uruguay<\/em>, which reaches 3.27 metres in height and weighs over 2.5 tonnes.<\/p>\n\n\n<p><span style=\"font-size: 18pt\"><strong>Sicilian Jasper<\/strong><\/span><\/p>\n<p>Referred to as <em>diaspri di Sicilia<\/em> in Italian, Sicilian jaspers are very hard and occur in a multitude of colour and pattern variations, making them ideal stones for ornamentation. Today they are no longer commercially quarried, but around 300 varieties of Sicilian jasper have been identified in the Baroque churches of Sicily. Reaching their heyday in the 17<sup>th<\/sup> and 18<sup>th<\/sup> centuries, Sicilian jaspers were mined mainly in the province of Palermo, particularly near the towns of Giuliana and Bisacquino.<\/p>\n<p>Jasper is a variety of opaque cryptocrystalline (the crystals cannot be seen, even under a microscope) quartz formed by silica-rich fluids percolating through fissures in limestone rocks. They come in an abundance of colours, with the red variations attributed to the presence of hematite and yellow to the presence of goethite. Brecciated jasper, which has a fragmented appearance, has formed due to movements of the rock, perhaps triggered by earthquakes. Like agates, jaspers can range from opaque to translucent and have a vitreous lustre.<\/p>\n<p>Thanks to the comprehensive Corsi collection mentioned above, it is possible for specialists\u00a0to identify varieties of Sicilian jasper used on decorative pieces. Present in The Courtauld\u2019s baroque frame are inlays of\u00a0<em>diaspro di Palermo<\/em>, which is a brecciated jasper with orange, red and colourless fragments (see Corsi 776 below), and two types of <em>diaspro di Giuliana<\/em>, one of which is a brecciated red jasper with rims of opaque white quartz (see Corsi 745 below), the other being a banded version of yellow and green layers (see Corsi 764 below).<\/p>\n\n<figure id=\"attachment_176\" aria-describedby=\"caption-attachment-176\" style=\"width: 300px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/OUMNH-Corsi0776.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-176 size-medium\" src=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/OUMNH-Corsi0776-300x141.jpg\" alt=\"\" width=\"300\" height=\"141\" srcset=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/OUMNH-Corsi0776-300x141.jpg 300w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/OUMNH-Corsi0776-768x360.jpg 768w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/OUMNH-Corsi0776-600x281.jpg 600w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/OUMNH-Corsi0776.jpg 877w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-176\" class=\"wp-caption-text\">Sicilian jasper &#8211; Corsi 776 \u00a9 Oxford University Museum of Natural History<\/figcaption><\/figure> <figure id=\"attachment_177\" aria-describedby=\"caption-attachment-177\" style=\"width: 300px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/OUMNH-Corsi0764.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-177 size-medium\" src=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/OUMNH-Corsi0764-300x143.jpg\" alt=\"\" width=\"300\" height=\"143\" srcset=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/OUMNH-Corsi0764-300x143.jpg 300w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/OUMNH-Corsi0764-768x366.jpg 768w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/OUMNH-Corsi0764-600x286.jpg 600w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/OUMNH-Corsi0764.jpg 858w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-177\" class=\"wp-caption-text\">Sicilian jasper &#8211; Corsi 764 \u00a9 Oxford University Museum of Natural History<\/figcaption><\/figure> <figure id=\"attachment_178\" aria-describedby=\"caption-attachment-178\" style=\"width: 300px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/OUMNH-Corsi0745.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-178 size-medium\" src=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/OUMNH-Corsi0745-300x148.jpg\" alt=\"\" width=\"300\" height=\"148\" srcset=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/OUMNH-Corsi0745-300x148.jpg 300w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/OUMNH-Corsi0745-768x379.jpg 768w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/OUMNH-Corsi0745-600x296.jpg 600w, https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/OUMNH-Corsi0745.jpg 855w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-178\" class=\"wp-caption-text\">Sicilian jasper &#8211; Corsi 745 \u00a9 Oxford University Museum of Natural History<\/figcaption><\/figure>\n\n<h2><span style=\"font-size: 18pt\"><strong>Acknowledgements<\/strong><\/span><\/h2>\n<p>\nI would like to thank Dr Ruth Siddall, Senior Lecturer in Earth Sciences at UCL, and Monica Price, \u00a0Collections Manager at the Oxford University Museum of Natural History, for their invaluable expertise in decorative stone identification, their continued guidance and their generosity in lending us rock and mineral samples from their collections for the display.\u00a0I also wish to thank the following scholars for their time and knowledgeable insight: Professor Aviva Burnstock, Professor and Head of the Department of Conservation and Technology at The Courtauld Institute of Art; Silvia Amato, PhD student and Technical Assistant at The Courtauld Institute of Art; Graeme Barraclough, Chief Conservator at The Courtauld Gallery; Matthew Thompson, Gallery Technician at The Courtauld Gallery; Dr Emma Passmore, Senior Teaching Fellow in Earth Sciences at Imperial College London; Nadine Gabriel, MSci Geology student at UCL; the furniture historian, Simon Jervis, as well as the frame historian, Lynn Roberts.<\/p>\n<h4>\u00a0<\/h4>\n<h2><span style=\"font-size: 18pt\"><strong>Bibliography<\/strong><\/span><\/h2>\n<p>\nBonewitz, Ronald Louis. <em>Rocks &amp; Minerals: The Definitive Visual Guide<\/em>, 2nd ed. London: Dorling Kindersley Limited, 2008.<\/p>\n<p>Cennini, Cennino. <em>The Craftsman&#8217;s Handbook : The Italian &#8220;Il Libro Dell Arte&#8221;<\/em>, trans. Daniel V Thompson Jr, 1st ed. New York: Dover Publications, 1960.<\/p>\n<p>Gonz\u00e1lez-Palacios, Alvar. \u2018Concerning Furniture: Roman Documents and Inventories\u2019.\u00a0<em>Furniture History<\/em>, Vol. 46 (2010): 1\u2013135.<\/p>\n<p>Koeppe, Wolfram, and Annamaria Giusti. <em>Art of the Royal Court: Treasures in Pietre Dure from the Palaces of Europe<\/em>. New York: Metropolitan Museum of Art, 2008.<\/p>\n<p>Pabian, Roger K., Brian Jackson, Peter Tandy and John Cromartie. <em>Agates: Treasures of the Earth<\/em>. London: Natural History Museum, 2006.<\/p>\n<p>Price, Monica T. <em>Decorative Stone: The Complete Sourcebook<\/em>. London: Thames &amp; Hudson, 2007.<\/p>\n<p>Price, Monica T., Lisa Cooke.\u00a0\u2018Corsi Collection of Decorative Stones\u2019, accessed 12 June 2020, <a href=\"http:\/\/www.oum.ox.ac.uk\/corsi\/\">http:\/\/www.oum.ox.ac.uk\/corsi\/<\/a><\/p>\n<p>Swynfen Jervis, Simon. &#8216;Review of <em>Arredi e Ornamenti alla Corte di Roma<\/em>\u00a0by Alvar Gonz\u00e1lez-Palacios\u2019.\u00a0<em>The Burlington Magazine<\/em>, Vol. 148, No. 1239 (2006): 422\u201323.<\/p>\n\n<\/div>\n<p>worked on this project during her MSc in Science Communication at Imperial College, London.<\/p>\n[aesop_parallax  height=&#8221;1500px&#8221; img=&#8221;https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/11\/frame2.jpg&#8221; parallaxbg=&#8221;fixed&#8221; parallaxspeed=&#8221;6&#8243; caption=&#8221;Anonymous maker, Portable altar frame, ebony with pietre dure decoration, first half of 17th century, 61 x 35 x 10 cm, \u00a9 The Samuel Courtauld Trust, The Courtauld Gallery, London, P.1978.PG.3&#8243; captionposition=&#8221;bottom-left&#8221; lightbox=&#8221;on&#8221; floater=&#8221;off&#8221; floaterposition=&#8221;left&#8221; floaterdirection=&#8221;none&#8221; overlay_revealfx=&#8221;off&#8221;]\n","protected":false},"excerpt":{"rendered":"<p>Natasha Gertler guides us around the many\u00a0 minerals that decorate a lavish 16th century portable altar. Natasha researched and produced this project during her MSc in Science Communication at Imperial College, London.\u00a0 [aesop_parallax height=&#8221;2000&#8243; img=&#8221;https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/11\/frame2.jpg&#8221; parallaxbg=&#8221;fixed&#8221; parallaxspeed=&#8221;6&#8243; caption=&#8221;Anonymous maker, Portable altar frame, ebony with pietre dure decoration, first half of 17th century, 61 x 35&hellip;<\/p>\n<p><a class=\"more-link\" href=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/objects\/17th-c-frame\/\" title=\"View &lsquo;A Baroque Pietre Dure Frame&rsquo;\">View <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":18,"featured_media":0,"parent":181,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"footnotes":""},"categories":[],"class_list":["post-74","page","type-page","status-publish","hentry"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.7 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>A Baroque Pietre Dure Frame - Illuminating Objects<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/objects\/17th-c-frame\/\" \/>\n<meta property=\"og:locale\" content=\"en_GB\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"A Baroque Pietre Dure Frame - Illuminating Objects\" \/>\n<meta property=\"og:description\" content=\"Natasha Gertler guides us around the many\u00a0 minerals that decorate a lavish 16th century portable altar. Natasha researched and produced this project during her MSc in Science Communication at Imperial College, London.\u00a0 [aesop_parallax height=&#8221;2000&#8243; img=&#8221;https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/11\/frame2.jpg&#8221; parallaxbg=&#8221;fixed&#8221; parallaxspeed=&#8221;6&#8243; caption=&#8221;Anonymous maker, Portable altar frame, ebony with pietre dure decoration, first half of 17th century, 61 x 35&hellip;View &rarr;\" \/>\n<meta property=\"og:url\" content=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/objects\/17th-c-frame\/\" \/>\n<meta property=\"og:site_name\" content=\"Illuminating Objects\" \/>\n<meta property=\"article:modified_time\" content=\"2020-07-17T14:39:41+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/sites.courtauld.ac.uk\/illuminating-objects\/wp-content\/uploads\/sites\/7\/2017\/05\/pallavicini-rome-frame-imperial-2017.jpg\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Estimated reading time\" \/>\n\t<meta name=\"twitter:data1\" content=\"14 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/sites.courtauld.ac.uk\\\/illuminating-objects\\\/objects\\\/17th-c-frame\\\/\",\"url\":\"https:\\\/\\\/sites.courtauld.ac.uk\\\/illuminating-objects\\\/objects\\\/17th-c-frame\\\/\",\"name\":\"A Baroque Pietre Dure Frame - 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