RARE EARTH
THE ART AND SCIENCE OF CHINESE STONES
This exhibition is co-organized by the Crow Museum of Asian Art of The University of Texas at Dallas and the Center for Asian Studies of The University of Texas at Dallas, in partnership with the UT Dallas Department of Geosciences and the Dr. Robert Lavinsky Mineral Collection.
GEOLOGICAL SCIENCE INFORMATION
Emerald (mineral): Emerald is the gemstone variety of the common mineral Beryl (chemical formula Be3Al2(SiO3)6). Emerald’s deep green color reflects trace amounts of the element chromium or sometimes vanadium. Beryl has a hardness of 7.5–8 on the 10 point Mohs scale (talc = 1, diamond = 10). Beryl forms by heating and squeezing in the crust as a result of metamorphism. Gold (mineral): Gold is a chemical element with the symbol Au (from Latin: aurum) and atomic number 79, making it one of the heaviest elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile metal in a pure form. Gold is one of the least reactive chemical elements (it doesn’t combine with oxygen to tarnish or rust) and is normally solid. Because of its scarcity and chemical inertness, gold was one of the first metals used by humans. Gold often occurs in free elemental (native) form as veins associated with plutonic igneous rocks or as nuggets in sediments, eroded from veins. Sandstone (rock): a clastic sedimentary rock. Most sandstones are composed of sand-sized grains of quartz and many have a lot of vacant “pore” space between grains. These pore spaces allow fluids to circulate through the rock, sometimes leading to diagenesis. The large sandstone from Jinhai Lake on view in the exhibition is a good example of sandstone diagenesis. Silver (mineral): Silver is a chemical element with the symbol Ag (from the Latin argentum) and atomic number 47. A soft, white, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. The metal is sometimes found in veins associated with plutonic igneous rocks in the pure, free elemental form (“native silver”), as an alloy with gold and other metals, and as parts of other minerals. Quartz (clear) (mineral): Quartz is a hard, crystalline mineral composed of four silicon atoms combined with four oxygens. The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of SiO2. Quartz is the second most abundant mineral in Earth’s continental crust, behind feldspar. Window glass is mostly made of silicon dioxide; like window glass, quartz is clear when there are no trace impurities. All quartz, colored or clear, has a hardness of 7 on the Mohs scale. Quartz (colored) (mineral): Quartz may be colored if there are trace amounts of metal such as iron incorporated in the mineral structure.