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  2. Quartz - Wikipedia

    en.wikipedia.org/wiki/Quartz

    Quartz is, therefore, classified structurally as a framework silicate mineral and compositionally as an oxide mineral. Quartz is the second most abundant mineral in Earth's continental crust, behind feldspar. [10] Quartz exists in two forms, the normal α-quartz and the high-temperature β-quartz, both of which are chiral. The transformation ...

  3. List of mineral tests - Wikipedia

    en.wikipedia.org/wiki/List_of_mineral_tests

    The Mohs Hardness Scale is the main scale to measure mineral hardness. Finger nail is 2.5, copper coin is 3.5, glass is 5.5 and steel is 6.5. Hardness scale is Talc is 1, Gypsum is 2, Calcite is 3, Fluorite is 4, Apatite is 5, Orthoclase Feldspar is 6, Quartz is 7, Topaz is 8, Corundum is 9 and Diamond is 10. Odor; Not always recommended.

  4. Zunyite - Wikipedia

    en.wikipedia.org/wiki/Zunyite

    Glassy, translucent, gray-tan, pseudohexagonal zunyite crystals on a milky quartz matrix. From the Big Bertha Mine, Dome Rock Mountains, La Paz County, Arizona (size: 3.3 x 3.2 x 2.8 cm)) Zunyite occurs in highly aluminous shales and hydrothermally altered volcanic rocks.

  5. List of minerals - Wikipedia

    en.wikipedia.org/wiki/List_of_minerals

    Amethyst crystals – a purple quartz Apophyllite crystals sitting right beside a cluster of peachy bowtie stilbite Aquamarine variety of beryl with tourmaline on orthoclase Arsenopyrite from Hidalgo del Parral, Chihuahua, Mexico Aurichalcite needles spraying out within a protected pocket lined by bladed calcite crystals Austinite from the Ojuela Mine, Mapimí, Durango, Mexico Ametrine ...

  6. Interference colour chart - Wikipedia

    en.wikipedia.org/wiki/Interference_colour_chart

    Michel-Lévy interference colour chart issued by Zeiss Microscopy. In optical mineralogy, an interference colour chart, also known as the Michel-Levy chart, is a tool first developed by Auguste Michel-Lévy to identify minerals in thin section using a petrographic microscope.

  7. Opal - Wikipedia

    en.wikipedia.org/wiki/Opal

    In gemology, opalescence is applied to the hazy-milky-turbid sheen of common or potch opal which does not show a play of color. [clarification needed] Opalescence is a form of adularescence. For gemstone use, most opal is cut and polished to form a cabochon. "Natural" opal refers to polished stones consisting wholly of precious opal.

  8. List of gemstones by species - Wikipedia

    en.wikipedia.org/wiki/List_of_gemstones_by_species

    Calcite. Manganoan calcite (var.); Caledonite; Canasite; Cancrinite. Vishnevite; Carletonite; Carnallite; Cassiterite; Catapleiite; Cavansite; Celestite; Ceruleite ...

  9. Inclusion (mineral) - Wikipedia

    en.wikipedia.org/wiki/Inclusion_(mineral)

    The term three phase relates to the three phases of matter, solid, liquid, and gas. This is a three phase inclusion in rock crystal quartz. The solid is a black material that is of bituminous origin. The liquid encased is petroleum, and the gas bubble is methane. Inclusions are one of the most important factors when it comes to gem valuation.