22 10 264 https://wserv3.esc.cam.ac.uk/p1acollections/files/original/7b2be47bf331c3137fab55b54dd00400.jpg 4df92e4c361bdf836240b34aa1def201 https://wserv3.esc.cam.ac.uk/p1acollections/files/original/a9feaa0d7b228322ef58f10eabce759a.jpg 2b6715ada6c2fb263e952153d2c695a1 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>Hematite</h2> Description An account of the resource <div class="element"> <h3>Formula</h3> <div class="element-text"> <p>Fe₂O₃</p> </div> </div> <div class="element"> <h3>Structure</h3> <div class="element-text"> <p>Non-silicate</p> </div> </div> <div class="element"> <h3>Crystal System</h3> <div class="element-text"> <p><em>Crystal system:</em><span> </span>trigonal (-)</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>black, steel-grey and bright to dull red</span><span> </span><br class="NoSpacing" /><em><span>Streak:</span></em><span> cherry-red</span><span> </span><br class="NoSpacing" /><em><span>Cleavage:</span></em><span> none</span><span> </span><br class="NoSpacing" /><em><span>Hardness:</span></em><span> 5-6</span></p> </div> </div> <div class="element"> <h3>Optical Properties</h3> <div class="element-text"> <p class="NoSpacing"><em><span>Colour in plane polarised light:</span></em><span> opaque; blood-red in very thin splinter</span><span> </span><br class="NoSpacing" /><em><span>Pleochroism:</span></em><span> none</span><span> </span><br class="NoSpacing" /><em><span>Relief:</span></em><span> high</span></p> </div> </div> <div class="element"> <h3>Mineral Specimens</h3> <div class="element-text"> <p class="NoSpacing"><strong><span>M500 Hematite</span></strong><span> </span><br class="NoSpacing" /><strong>Cumberland</strong><strong></strong><span> </span><br class="NoSpacing" />A concretionary mass showing concentric and radial structure<span> </span><br class="NoSpacing" />Silvery black with a red streak<span> </span><br class="NoSpacing" />Oxidised to dark brown-red in places<span> </span><br />Metallic lustre</p> </div> </div> <div class="element"> <h3>Rock Specimens</h3> <div class="element-text"> <p><a href="/p1acollections/exhibits/show/sedimentary-rocks/l310">L310 Breccia</a><span> </span><br /><a href="/p1acollections/exhibits/show/sedimentary-rocks/l311">L311 Conglomerate</a><span> </span><br /><a href="/p1acollections/exhibits/show/sedimentary-rocks/l324">L324 Sandstone, feldspathic arenite</a><span> </span><br /><a href="/p1acollections/exhibits/show/sedimentary-rocks/l326">L326 Sandstone, ferruginous arenite</a><span> </span><br /><a href="/p1acollections/exhibits/show/sedimentary-rocks/l340">L340 Mudstone</a><span> </span><br /><a href="/p1acollections/exhibits/show/sedimentary-rocks/l354">L354 Limestone, shelly</a><br /><a href="/p1acollections/exhibits/show/metamorphic-rocks/l500">L500 Slate</a></p> </div> </div> <div class="element"> <h3>Mineral Name</h3> <div class="element-text">hematite<br />iron oxide<br />opaques</div> </div> oxidation sedimentary https://wserv3.esc.cam.ac.uk/p1acollections/files/original/0bf5d3a466fa7829e4ef2bdff830625a.jpg 6cd884f723303bde9f49b486c09d2b91 https://wserv3.esc.cam.ac.uk/p1acollections/files/original/26bbd90e23750b6cd8f025a7c4477901.jpg a7e67bd99ca02148d530d0f06a0cc68b https://wserv3.esc.cam.ac.uk/p1acollections/files/original/301029738940ac75d82ed2ef3b0d90b2.jpg a9a01f476ba1204e36ea0f961c5793d6 https://wserv3.esc.cam.ac.uk/p1acollections/files/original/96e67e3861b4a7dcb407f3b5f225bb27.jpg 30e1e24259599004ba7c7f6d73bf6953 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>Quartz</h2> Description An account of the resource <div class="element"> <h3>Formula</h3> <div class="element-text">SiO₂</div> </div> <div class="element"> <h3>Structure</h3> <div class="element-text"> <p>Framework silicate</p> </div> </div> <div class="element"> <h3>Crystal System</h3> <div class="element-text"> <p><em>Crystal system:</em><span> </span>trigonal (+)</p> </div> </div> <div class="element"> <h3>Physical Properties</h3> <div class="element-text"> <p class="NoSpacing"><em>Colour in hand specimen:</em><span> </span>colourless<span> </span><br class="NoSpacing" /><em>Lustre:</em><span> </span>vitreous<span> </span><br class="NoSpacing" /><em>Pleochroism:</em><span> </span>none<span> </span><br class="NoSpacing" /><em>Cleavage:</em><span> </span>none<span> </span><br /><em>Hardness:</em><span> </span>7</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<span> </span><br class="NoSpacing" /><em>Pleochroism:</em><span> </span>none<span> </span><br class="NoSpacing" /><em>Relief:</em><span> </span>low<span> </span><br /><em>Birefringence:</em><span> </span>0.009; 1^st<span> </span>order grey</p> </div> </div> <div class="element"> <h3>Mineral Specimens</h3> <div class="element-text"> <p class="NoSpacing"><strong><span>M410 </span></strong><strong><span>Quartz</span></strong><span> </span><br class="NoSpacing" />Characteristic prismatic crystal form: hexagonal cross-section, needle-like; hexagonal prism surmounted by a hexagonal pyramid<span> </span><br class="NoSpacing" />Colourless, transparent, milky in places<span> </span><br class="NoSpacing" /><strong></strong></p> <p class="NoSpacing"><strong><span>M411 </span></strong><strong><span>Quartz</span></strong><span> </span><br class="NoSpacing" /><strong>Madagascar</strong><strong></strong><span> </span><br class="NoSpacing" />Colourless, transparent quartz fragment, milky due to cracks and crystal boundaries<span> </span><br class="NoSpacing" />Vitreous lustre, conchoidal fracture, no cleavage</p> <p class="NoSpacing"><strong><span>M412 </span></strong><strong><span>Quartz (with galena and pyrite)</span></strong><span> </span><br class="NoSpacing" /><strong>North Wales</strong><strong></strong><span> </span><br class="NoSpacing" />A mass of small hexagonal quartz prisms, with galena, pyrite and zinc blende.<span> </span><br class="NoSpacing" />Transparent, white to light grey<span> </span><br class="NoSpacing" />Galena: purple-black, shiny, platy habit, metallic<span> </span><br class="NoSpacing" />Pyrite: metallic lustre, gold colour, cubic habit, “Fools’ gold”</p> </div> </div> <div class="element"> <h3>Rock Specimens</h3> <div class="element-text"> <p><a href="/p1acollections/exhibits/show/igneous-rocks/l101">L101 Granite</a><span> </span><br /><a href="/p1acollections/exhibits/show/igneous-rocks/l110">L110 Rhyolite, porphyritic (quartz porphyry)</a><span> </span><br /><a href="/p1acollections/exhibits/show/igneous-rocks/l120">L120 Granodiorite</a><span> </span><br /><a href="/p1acollections/exhibits/show/sedimentary-rocks/l311">L311 Conglomerate, matrix</a><span> </span><br /><a href="/p1acollections/exhibits/show/sedimentary-rocks/l323">L323 Sandstone, arenite</a><span> </span><br /><a href="/p1acollections/exhibits/show/sedimentary-rocks/l370">L370 Chert, flint nodule, cryptocrystalline</a><span> </span><br /><a href="/p1acollections/exhibits/show/metamorphic-rocks/l504">L504 Garnet schist</a><span> </span><br /><a href="/p1acollections/exhibits/show/metamorphic-rocks/l521">L521 Quartzite</a></p> </div> </div> <div class="element"> <h3>Mineral Name</h3> <div class="element-text">silica<br />quartz</div> </div> igneous metamorphic milky sedimentary vitreous https://wserv3.esc.cam.ac.uk/p1acollections/files/original/2f7362a5c5cc5e00bc17ca856238ee37.jpg 44db79a97ef535c74d897e9db008bca0 https://wserv3.esc.cam.ac.uk/p1acollections/files/original/94761134fac46b7078906210b5bb3b8f.jpg 323c8b77db6400b701b97ff8bcaa92f2 https://wserv3.esc.cam.ac.uk/p1acollections/files/original/de6097beca8b60a758b218148982f48d.jpg cc38a8962e52d9ea6bf655b0c40038cd 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>Plagioclase feldspar</h2> Description An account of the resource <div class="element"> <h3>Formula</h3> <div class="element-text"> <p>Na[AlSi₃O₈] – Ca[Al₂Si₂O₈]</p> </div> </div> <div class="element"> <h3>Structure</h3> <div class="element-text"> <p>Framework silicate</p> </div> </div> <div class="element"> <h3>Crystal System</h3> <div class="element-text"> <p><em>Crystal system:</em><span> </span>triclinic (+) (-)</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> white</span><span> </span><br class="NoSpacing" /><em><span>Cleavage:</span></em><span> two at 90°</span><span> </span><br class="NoSpacing" /><em><span>Hardness:</span></em><span> 6-6.5</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<span> </span><br class="NoSpacing" /><em>Pleochroism:</em><span> </span>none<span> </span><br class="NoSpacing" /><em>Relief:</em><span> </span>low<span> </span><br class="NoSpacing" /><em>Birefringence:</em><span> </span>~0.010, 1^st<span> </span>order grey<span> </span><br class="NoSpacing" /><em>Extinction:</em><span> </span>inclined<span> </span><br class="NoSpacing" /><em>Twinning:</em><span> </span>lamellar, very common</p> </div> </div> <div class="element"> <h3>Mineral Specimens</h3> <div class="element-text"> <p class="NoSpacing"><strong><span>M403 </span></strong><strong><span>Plagioclase feldspar, oligoclase</span></strong><span> </span><br class="NoSpacing" /><strong>Ytterby</strong><strong>, Sweden</strong><strong></strong><span> </span><br class="NoSpacing" />A cleavage fragment of white plagioclase feldspar<span> </span><br class="NoSpacing" />Pearly lustre on cleavage planes<span> </span><br class="NoSpacing" />Two sets of cleavage at 90°<span> </span><br class="NoSpacing" />Fine parallel striations due to lamellar twinning</p> <p class="NoSpacing"><strong><span>M404 </span></strong><strong><span>Plagioclase feldspar, labradorite</span></strong><span> </span><br class="NoSpacing" /><strong>Labrador</strong><strong></strong><span> </span><br class="NoSpacing" />Dark grey, light where fragments are small due to cracking along cleavage<span> </span><br class="NoSpacing" />Schiller (blue iridescence), characteristic of labradorite<span> </span><br class="NoSpacing" />Very fine parallel striations due to lamellar twinning</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 /><a href="/p1acollections/exhibits/show/igneous-rocks/l101">L101 Granite</a><span> </span><br /><a href="/p1acollections/exhibits/show/igneous-rocks/l102">L102 Hornblende biotite granite</a><span> </span><br /><a href="/p1acollections/exhibits/show/igneous-rocks/l112">L112 Rhyolite</a><span> </span><br /><a href="/p1acollections/exhibits/show/igneous-rocks/l120">L120 Granodiorite</a><span> </span><br /><a href="/p1acollections/exhibits/show/igneous-rocks/l130">L130 Andesite, porphyritic (porphyrite)</a><span> </span><br /><a href="/p1acollections/exhibits/show/igneous-rocks/l141">L141 Gabbro</a><span> </span><br /><a href="/p1acollections/exhibits/show/igneous-rocks/l162">L162 Basalt, porphyritic</a><span> </span><br /><a href="/p1acollections/exhibits/show/igneous-rocks/l172">L172 Ultramafic cumulate</a><span> </span><br /><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 class="NoSpacing"><span>Plagioclase feldspar forms a continuous solid solution between the sodic endmember (albite, or Ab) and the calcic endmember (anorthite, or An). The series is sub-divided into albite (An_0-10), oligoclase (An_10-30) andesine (An_30-50), labradorite (An_50-70), bytownite (An_70-90) and anorthite (An_90-100).</span></p> </div> </div> <div class="element"> <h3>Mineral Name</h3> <div class="element-text">plagioclase<br />feldspar</div> </div> felsic igneous mafic metamorphic sedimentary https://wserv3.esc.cam.ac.uk/p1acollections/files/original/7eda87156991f7c8b27a0e8510940358.jpg 2635d861ca5b4c2cbbd828726c95bfd4 https://wserv3.esc.cam.ac.uk/p1acollections/files/original/dcc7eadcc1e8adacfb3ca0062cf15b41.jpg 35dd6efe13e1fca981d0837a56294e0b https://wserv3.esc.cam.ac.uk/p1acollections/files/original/4df0492facb5854e9375d2f627f192fe.jpg ffc9075681e5de8a163ba2009ad46bb1 https://wserv3.esc.cam.ac.uk/p1acollections/files/original/52688639ee0b849fb604e43c822c434b.jpg 27a1d7561ed102f3dc1de4996962dd8d 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>Alkali feldspar</h2> Description An account of the resource <div class="element"> <div class="element"> <h3>Formula</h3> <div class="element-text"> <p>(K,Na)[AlSi₃O₈]</p> </div> </div> <div class="element"> <h3>Structure</h3> <div class="element-text"> <p>Framework silicate</p> </div> </div> <div class="element"> <h3>Crystal System</h3> <div class="element-text"> <p><em>Crystal system:</em><span> </span>monoclinic (-) or triclinic (+) (-)</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> white or pink</span><span> </span><br class="NoSpacing" /><em><span>Cleavage:</span></em><span> two at 90°</span><span> </span><br class="NoSpacing" /><em><span>Hardness:</span></em><span> 6-6.5</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<span> </span><br class="NoSpacing" /><em>Pleochroism:</em><span> </span>none<span> </span><br class="NoSpacing" /><em>Relief:</em><span> </span>low<span> </span><br class="NoSpacing" /><em>Birefringence:</em><span> </span>~0.008; 1^st<span> </span>order greys<span> </span><br class="NoSpacing" /><em>Extinction:</em><span> </span>inclined<span> </span><br class="NoSpacing" /><em>Twinning: </em>usually simple or lamellar;<span> </span><br />              Microcline (KAlSi₃O₈) displays characteristic cross-hatched twinning</p> </div> </div> <div class="element"> <h3>Mineral Specimens</h3> <div class="element-text"> <p class="NoSpacing"><strong><span>M400 </span></strong><strong><span>Alkali feldspar, microcline</span></strong><span> </span><br class="NoSpacing" />A single crystal of pale orange-pink alkali feldspar.<span> </span><br class="NoSpacing" />Pearly lustre.</p> <p class="NoSpacing"><strong><span>M401 </span></strong><strong><span>Alkali feldspar, orthoclase</span></strong><span> </span><br class="NoSpacing" /><strong>Norway</strong><strong></strong><span> </span><br class="NoSpacing" />A fragment of opaque, pale grey alkali feldspar.<span> </span><br class="NoSpacing" />Two sets of good cleavage at right angles, with a pearly lustre on the cleavage faces.</p> <p class="NoSpacing"><strong><span>M402 </span></strong><strong><span>Alkali feldspar, orthoclase</span></strong><span> </span><br class="NoSpacing" /><strong>Shap, Westmorland</strong><span> </span><br class="NoSpacing" />Porphyritic granite.<span> </span><br class="NoSpacing" />Large phenocrysts of pink feldspar, two sets of cleavage at 90°, simple twinning.<span> </span><br class="NoSpacing" />Also white plagioclase feldspar, quartz and biotite<strong>.</strong></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 /><a href="/p1acollections/exhibits/show/igneous-rocks/l101">L101 Granite</a><span> </span><br /><a href="/p1acollections/exhibits/show/igneous-rocks/l102">L102 Hornblende biotite granite</a><span> </span><br /><a href="/p1acollections/exhibits/show/igneous-rocks/l110">L110 Rhyolite, porphyritic (quartz porphyry)</a></p> </div> </div> <div class="element"> <h3>Mineral Name</h3> <div class="element-text">alkali feldspar</div> </div> </div> felsic granite rhyolite https://wserv3.esc.cam.ac.uk/p1acollections/files/original/6667ec467cbdbb73c1ac797cbd273fd0.jpg 583f6ed4a44b73689a712abe98dec971 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>Serpentine</h2> Subject The topic of the resource <span>Serpentine is a common alteration product of olivine, produced by hydration at low temperatures.</span> Description An account of the resource <div class="element"> <h3>Formula</h3> <div class="element-text"> <p>Mg₃[Si₂O₅](OH)₄</p> </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 or orthorhombic (-)</p> </div> </div> <div class="element"> <h3>Optical Properties</h3> <div class="element-text"> <p class="NoSpacing"><span>Serpentine is commonly very fine-grained. It can be recognised by its textural association with olivine and by its low birefringence and habit.</span></p> <p class="NoSpacing"><em><span>Colour in plane polarised light:</span></em><span> green</span><span> </span><br class="NoSpacing" /><em><span>Relief:</span></em><span> low</span><span> </span><br class="NoSpacing" /><em><span>Birefringence:</span></em><span> 1^st order</span></p> </div> </div> <div class="element"> <h3>Rock Specimens</h3> <div class="element-text"> <p><a href="/p1acollections/exhibits/show/igneous-rocks/l141">L141 Gabbro</a><span> </span><br /><a href="/p1acollections/exhibits/show/igneous-rocks/l162">L162 Basalt, porphyritic</a><span> </span><br /><a href="/p1acollections/exhibits/show/igneous-rocks/l172">L172 Ultramafic cumulate</a></p> </div> </div> <div class="element"> <h3>Mineral Name</h3> <div class="element-text">serpentine</div> </div> alteration hydration olivine 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/20b9609f2cc656507a1fec2347d9df89.jpg fa472417a23e56ecbb9b556d05c4ffca https://wserv3.esc.cam.ac.uk/p1acollections/files/original/3404979c4792fa74731a7e04e3022017.jpg 599a58e88705064fd972b61f03d15f68 https://wserv3.esc.cam.ac.uk/p1acollections/files/original/65c206021f6f75651f1697f0cd29cf1d.jpg 06b1f7e0df480b95e954641fe6339f67 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>Mica, biotite</h2> Description An account of the resource <div class="element"> <h3>Formula</h3> <div class="element-text">K₂(Mg,Fe²⁺)_6-4(Fe³⁺,Al,Ti)_0-2[Si_6-5Al_2-3O₂₀](OH,F)₄</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 class="NoSpacing"><em><span>Crystal</span></em><em><span> system:</span></em><span> monoclinic (-)</span></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> brown or black</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><span>Colour in plane polarised light:</span></em><span> pale yellow, pale green, green or brown</span><span> </span><br /><em><span>Pleochroism:</span></em><span> strong</span><span> </span><br /><em><span>Relief:</span></em><span> low</span><span> </span><br /><em><span>Birefringence: </span></em><span>0.028-0.08; 2^nd order green-yellow to &gt;4^th order</span><span> </span><em><span><br />Extinction: </span></em><span>straight</span></p> </div> </div> <div class="element"> <h3>Mineral Specimens</h3> <div class="element-text"> <p class="NoSpacing"><strong><span>M303 </span></strong><strong><span>Mica, biotite</span></strong><span> </span><br class="NoSpacing" /><strong>Cornwall</strong><strong></strong><span> </span><br class="NoSpacing" />Large irregular biotite crystals in a feathery arrangement<span> </span><br class="NoSpacing" />Dark brown / black / golden<span> </span><br class="NoSpacing" />Metallic lustre<span> </span><br class="NoSpacing" />Platy habit due to the single perfect cleavage</p> <p class="NoSpacing"><strong><span>M304 </span></strong><strong><span>Mica, biotite</span></strong><span> </span><br class="NoSpacing" /><strong>Orlando</strong><strong>, Canada</strong><strong></strong><span> </span><br class="NoSpacing" />Irregular plates of biotite split along cleavage planes<span> </span><br class="NoSpacing" />One good cleavage<span> </span><br class="NoSpacing" />Brilliant metallic lustre</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 /><a href="/p1acollections/exhibits/show/igneous-rocks/l101">L101 Granite</a><span> </span><br /><a href="/p1acollections/exhibits/show/igneous-rocks/l102">L102 Hornblende biotite granite</a><span> </span><br /><a href="/p1acollections/exhibits/show/igneous-rocks/l120">L120 Granodiorite</a><span> </span><br /><a href="/p1acollections/exhibits/show/igneous-rocks/l130">L130 Andesite, porphyritic (porphyrite)</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">mica<br />biotite</div> </div> basal cleavage igneous metapelite https://wserv3.esc.cam.ac.uk/p1acollections/files/original/f45fcf901e391b706d58c5a76ce9e0f7.jpg 0b887bd5e1ae09a04261e9bb9af69078 https://wserv3.esc.cam.ac.uk/p1acollections/files/original/daa51ed8284e2f268043c893ed2835dc.jpg 1c07f39572ce1f39720e395b2d729c83 https://wserv3.esc.cam.ac.uk/p1acollections/files/original/f85892ba7ce86764f8dafc18adab40a6.jpg e9b02c931f4847fb3d65e56480cc42d2 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>Mica, muscovite</h2> Description An account of the resource <div class="element"> <h3>Formula</h3> <div class="element-text">K₂Al₄[Si₆Al₂O₂₀](OH,F)₄</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> colourless</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> 2.5-3</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<span> </span><br class="NoSpacing" /><em>Pleochroism:</em><span> </span>none<span> </span><br class="NoSpacing" /><em>Relief:</em><span> </span>low<span> </span><br class="NoSpacing" /><em>Birefringence:<span> </span></em>0.036-0.049; 2^nd<span> </span>order pink to 3^rdorder yellow<span> </span><br /><em>Extinction: </em>straight</p> </div> </div> <div class="element"> <h3>Mineral Specimens</h3> <div class="element-text"> <p class="NoSpacing"><strong><span>M301 </span></strong><strong><span>Mica, muscovite</span></strong><span> </span><br class="NoSpacing" /><strong>Lincoln County</strong><strong>, North Carolina</strong><strong></strong><span> </span><br class="NoSpacing" />Well-formed tabular crystals showing the pseudohexangonal symmetry<span> </span><br class="NoSpacing" />Colourless, mirror- like, metallic lustre<span> </span><br class="NoSpacing" />Platy, flaky habit<span> </span><br class="NoSpacing" />Soft</p> <p class="NoSpacing"><strong><span>M302 </span></strong><strong><span>Mica, muscovite</span>   <span> </span></strong><br class="NoSpacing" /><strong>Mysore</strong><strong>, India</strong><strong></strong><span> </span><br class="NoSpacing" />Plates of mica artificially cut to shape<span> </span><br class="NoSpacing" />Colourless<span> </span><br class="NoSpacing" />One perfect cleavage</p> </div> </div> <div class="element"> <h3>Rock Specimens</h3> <div class="element-text"> <p><a href="/p1acollections/exhibits/show/igneous-rocks/l110">L110 Rhyolite, porphyritic (quartz porphyry)</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">mica<br />muscovite</div> </div> basal cleavage igneous metapelite https://wserv3.esc.cam.ac.uk/p1acollections/files/original/be33d89fe6d9036ae8352a6f3f9a84ad.jpg c11d5dd9223d779156b594135bba0756 https://wserv3.esc.cam.ac.uk/p1acollections/files/original/6674f7f49c2139327e03ef9b7487f568.jpg 434535ac740cdd1dd8093026a4e67be7 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>Amphibole (hornblende)</h2> Description An account of the resource <div class="element"> <h3>Formula</h3> <div class="element-text"> <p>(Na,K)_0-1Ca₂(Mg,Fe²⁺,Fe³⁺,Al)₅Si_6-7.5Al_2-0.5O₂₂(OH)₂</p> </div> </div> <div class="element"> <h3>Structure</h3> <div class="element-text"> <p>Chain silicate</p> </div> </div> <div class="element"> <h3>Crystal System</h3> <div class="element-text"> <p class="NoSpacing"><em><span>Crystal</span></em><em><span> system: </span></em><span>monoclinic (+) (-)</span></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> black</span><span> </span><br class="NoSpacing" /><em><span>Cleavage:</span></em><span> two at ~56°</span><span> </span><br class="NoSpacing" /><em><span>Hardness:</span></em><span> 5-6</span></p> </div> </div> <div class="element"> <h3>Optical Properties</h3> <div class="element-text"> <p class="NoSpacing"><em><span>Colour in plane polarised light:</span></em><span> pale green, green, light yellow-brown to brown</span><span> </span><br class="NoSpacing" /><em><span>Pleochroism:</span></em><span> yes</span><span> </span><br class="NoSpacing" /><em><span>Relief:</span></em><span> moderate</span><span> </span><br class="NoSpacing" /><em><span>Birefringence:</span></em><span> ~0.02; 2^nd order purple</span><span> </span><br class="NoSpacing" /><em><span>Extinction:</span></em><span> inclined</span><span> </span><br class="NoSpacing" /><em><span>Twinning:</span></em><span> simple, lamellar, common</span></p> </div> </div> <div class="element"> <h3>Mineral Specimens</h3> <div class="element-text"> <p><strong><span>M210 </span></strong><strong><span>Amphibole, hornblende</span></strong><span> </span><br /><strong>Bilen, Bohemia</strong><span> </span><br />Single, black prismatic<strong><span> </span></strong>crystal.<span> </span><br />At the ends of the crystal two sets of cleavage planes are visible, intersecting at ~56°</p> <p><strong><span>M211 </span></strong><strong><span>Amphibolite</span></strong><span> </span><br /><strong>Isle of Coll, Inner Hebrides</strong><span> </span><br />A metamorphic rock consisting almost entirely of crystals of the amphibole hornblende<span> </span><br />Black<span> </span><br />Brilliant lustre<span> </span><br />Two sets of cleavage planes intersect at ~56°</p> </div> </div> <div class="element"> <h3>Rock Specimens</h3> <div class="element-text"> <p><a href="/p1acollections/exhibits/show/igneous-rocks/l102">L102 Hornblende biotite granite</a><span> </span><br /><a href="/p1acollections/exhibits/show/igneous-rocks/l120">L120 Granodiorite</a></p> </div> </div> <div class="element"> <h3>Advanced Notes</h3> <div class="element-text"> <p class="NoSpacing"><span>The amphibole group encompasses a wide range of compositions. Even the hornblendes, which are a sub-group of the amphiboles, encompass a range of compositions (see mineral formula, above). The properties above refer to hornblende.</span></p> </div> </div> <div class="element"> <h3>Mineral Name</h3> <div class="element-text">amphibole<br />hornblende</div> </div> igneous metabasite https://wserv3.esc.cam.ac.uk/p1acollections/files/original/ac4a4b68b6b2ad4fef27b63699c1a3bf.jpg 7f450bfca482d0fe4649c3f6f70d4afa 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>Clinopyroxene (augite)</h2> Description An account of the resource <div class="element"> <h3>Formula</h3> <div class="element-text">(Ca,Mg,Fe²⁺,Fe³⁺,Ti,Al)₂[(Si,Al)₂O₆]</div> </div> <div class="element"> <h3>Structure</h3> <div class="element-text"> <p>Chain silicate</p> </div> </div> <div class="element"> <h3>Crystal System</h3> <div class="element-text"> <p><em>Crystal</em><em><span> </span>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> black</span><span> </span><br class="NoSpacing" /><em><span>Cleavage:</span></em><span> two at 90°</span><span> </span><br class="NoSpacing" /><em><span>Hardness:</span></em><span> 5.5-6</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, pale brown or pale grey<span> </span><br class="NoSpacing" /><em>Pleochroism:</em><span> </span>variable weak to moderate<span> </span><br class="NoSpacing" /><em>Relief:</em><span> </span>moderate<span> </span><br class="NoSpacing" /><em>Birefringence:</em><span> </span>0.018-0.033; 1^st<span> </span>order pink to 2^nd<span> </span>order orange<span> </span><br class="NoSpacing" /><em>Extinction:</em><span> </span>inclined<span> </span><em><br />Twinning:</em><span> </span>simple, common</p> </div> </div> <div class="element"> <h3>Rock Specimens</h3> <div class="element-text"> <p><a href="/p1acollections/exhibits/show/igneous-rocks/l141">L141 Gabbro</a><span> </span><br /><a href="/p1acollections/exhibits/show/igneous-rocks/l161">L161 Basalt, amygdaloidal</a><span> </span><br /><a href="/p1acollections/exhibits/show/igneous-rocks/l162">L162 Basalt, porphyritic</a><span> </span><br /><a href="/p1acollections/exhibits/show/igneous-rocks/l172">L172 Ultramafic cumulate</a></p> </div> </div> <div class="element"> <h3>Advanced Notes</h3> <div class="element-text"> <p class="NoSpacing"><span>Clinopyroxene contains calcium. It encompasses a range of solid solutions from (Mg,Fe)₂[Si₂O₆] to Ca(Mg,Fe)[Si₂O₆]. The physical and optical properties detailed above refer to augite, a clinopyroxene common in mafic igneous rocks.</span></p> </div> </div> <div class="element"> <h3>Mineral Name</h3> <div class="element-text">clinopyroxene<br />augite</div> </div> mafic ultramafic