1 10 3 https://wserv3.esc.cam.ac.uk/p1acollections/files/original/696687461afd25ae14285b6fab757bfc.jpg 6283ac65e1ab3970a7982cdbaf1f06d7 Physical Object An inanimate, three-dimensional object or substance. Note that digital representations of, or surrogates for, these objects should use Moving Image, Still Image, Text or one of the other types. Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource <h2>Chlorite</h2> Subject The topic of the resource <span>Chlorite is a common high-temperature alteration product of ferromagnesian minerals (such as biotite) in igneous rocks. It is stable in the upper part of the crust and is a major constituent of the metamorphic rocks known as greenschists.</span> Description An account of the resource <div class="element-set"> <div class="element"> <div class="element-text"> <h3 class="NoSpacing">Formula</h3> </div> </div> </div> <div class="element-set"> <div class="element"> <div class="element-text">(Mg,Fe²⁺,Fe³⁺,Mn,Al)₁₂[(Si,Al)₈O₂₀](OH)₁₆</div> </div> <div class="element"> <h3>Structure</h3> <div class="element-text"> <p>Sheet silicate</p> </div> </div> <div class="element"> <h3>Crystal System</h3> <div class="element-text"> <p><em>Crystal system:</em><span> </span>monoclinic (+) (-)</p> </div> </div> <div class="element"> <h3>Physical Properties</h3> <div class="element-text"> <p class="NoSpacing"><em><span>Colour in hand specimen:</span></em><span> green</span><span> </span><br class="NoSpacing" /><em><span>Cleavage:</span></em><span> one, good</span><span> </span><br class="NoSpacing" /><em><span>Hardness:</span></em><span> 2-3</span></p> </div> </div> <div class="element"> <h3>Optical Properties</h3> <div class="element-text"> <p class="NoSpacing"><em>Colour in plane polarised light:</em><span> </span>colourless or green<span> </span><br class="NoSpacing" /><em>Pleochroism:</em><span> </span>weak to moderate<span> </span><br class="NoSpacing" /><em>Relief:</em><span> </span>low<span> </span><br class="NoSpacing" /><em>Birefringence:</em><span> </span>anomalous (blue or brown colours that do not appear in the Michel-Levy chart)<span> </span><br /><em>Extinction:</em><span> </span>straight</p> </div> </div> <div class="element"> <h3>Rock Specimens</h3> <div class="element-text"> <p><a href="/p1acollections/exhibits/show/igneous-rocks/l100">L100 Alkali granite</a><span> </span><br class="NoSpacing" /><a href="/p1acollections/exhibits/show/igneous-rocks/l101">L101 Granite</a><span> </span><br class="NoSpacing" /><a href="/p1acollections/exhibits/show/igneous-rocks/l120">L120 Granodiorite</a><span> </span><br class="NoSpacing" /><a href="/p1acollections/exhibits/show/igneous-rocks/l130">L130 Andesite, porphyritic (porphyrite)</a><span> </span><br class="NoSpacing" /><a href="/p1acollections/exhibits/show/igneous-rocks/l161">L161 Basalt, amygdaloidal</a><span> </span><br /><a href="/p1acollections/exhibits/show/volcaniclastic-rocks/l201">L201 Tuff</a><span> </span><br /><a href="/p1acollections/exhibits/show/metamorphic-rocks/l504">L504 Garnet schist</a></p> </div> </div> <div class="element"> <h3>Mineral Name</h3> <div class="element-text">chlorite</div> </div> </div> alteration metamorphism https://wserv3.esc.cam.ac.uk/p1acollections/files/original/74710dbf85be2a6e9e238ba537ef6ad4.jpg 28595880e272b17b8a23671cdc97d677 Physical Object An inanimate, three-dimensional object or substance. Note that digital representations of, or surrogates for, these objects should use Moving Image, Still Image, Text or one of the other types. Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource <h2>Garnet</h2> Description An account of the resource <div class="element"> <h3>Formula</h3> <div class="element-text">(Mg,Fe,Ca)₃Al₂Si₃O₁₂</div> </div> <div class="element"> <h3>Structure</h3> <div class="element-text"> <p>Orthosilicate</p> </div> </div> <div class="element"> <h3>Crystal System</h3> <div class="element-text"> <p><em>Crystal system:</em><span> </span>cubic</p> </div> </div> <div class="element"> <h3>Physical Properties</h3> <div class="element-text"> <p><em>Colour in hand specimen:</em><span> </span>typically red<br /><em>Cleavage:</em><span> </span>none<br /><em>Hardness:</em><span> </span>6-7.5</p> </div> </div> <div class="element"> <h3>Optical Properties</h3> <div class="element-text"> <p><em>Colour in plane polarised light:</em><span> </span>colourless, pale pink<span> </span><br /><em>Pleochroism:</em><span> </span>none<br /><em>Relief:</em><span> </span>high<br />Isotropic</p> </div> </div> <div class="element"> <h3>Mineral Specimens</h3> <div class="element-text"> <p><span><strong>M130 Garnet schist</strong></span><br /><strong>Portsoy, Banffshire</strong><br />Euhedral porphyroblasts of dark-red garnet, with quartz, mica and other minerals in a medium-grade metamorphic rock.</p> </div> </div> <div class="element"> <h3>Rock Specimens</h3> <div class="element-text"> <p><a href="/p1acollections/exhibits/show/metamorphic-rocks/l504">L504 Garnet schist</a></p> </div> </div> <div class="element"> <h3>Advanced Notes</h3> <div class="element-text"> <p>The garnet group encompasses a wide range of compositions, and consequently a range of optical and physical properties. The properties detailed above are typical of pyrope (Mg₃Al₂Si₃O₁₂), almandine (Fe²⁺₃Al₂Si₃O₁₂) and grossular (Ca₃Al₂Si₃O₁₂).</p> </div> </div> <div class="element"> <h3>Mineral Name</h3> <div class="element-text">garnet</div> </div> metamorphism metapelite https://wserv3.esc.cam.ac.uk/p1acollections/files/original/ccf4a152eba569461bf6ef055f4b1967.jpg 09fce135a7daa260d1040c49fa782944 https://wserv3.esc.cam.ac.uk/p1acollections/files/original/f138a19e1e584077538e0a5fb26e22db.jpg 01aab9478722295690d2c9ca02f53a9b https://wserv3.esc.cam.ac.uk/p1acollections/files/original/8bb0c75035b89eb9fa8462899036cdf4.jpg 4ac94845dc4d2450665869ea8855f2ea Physical Object An inanimate, three-dimensional object or substance. Note that digital representations of, or surrogates for, these objects should use Moving Image, Still Image, Text or one of the other types. Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource <h2><strong>L201<br /></strong></h2> <h2>Tuff</h2> Description An account of the resource <div class="element"> <h3>Hand Specimen</h3> <div class="element-text"> <p>Fine-grained, blue-green, sedimentary texture.<span> </span><br />Slaty<span> </span><a href="/p1acollections/items/show/180">cleavage</a>.<span> </span><br />Some patches of lighter and finer-grained material.</p> </div> </div> <div class="element"> <h3>Thin-section</h3> <div class="element-text"> <p>Slaty cleavage due to the alignment of chlorite and muscovite.<span> </span><br />Cross-cut by the blobs of the fine-grained material. These are orange-brown in thin-section. Could be water-lain ash, ripped-up to form clasts.<span> </span><br />Very fine-grained, brown matrix, probably<span> </span><a href="/p1acollections/items/show/266">volcanic</a><span> </span>ash.<span> </span><br />Carbonate, quartz and opaque clasts slightly larger than the matrix.</p> </div> </div> <div class="element"> <h3>Rock History</h3> <div class="element-text">Fine-grained volcanic ash deposited by an explosive volcanic eruption has undergone low grade metamorphism to produce a slaty cleavage.</div> </div> <div class="element"></div> <div class="element"></div> <div class="element"> <h3>Rock Name</h3> <div class="element-text">tuff</div> </div> cleavage metamorphism slaty