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Leaders of states in the U.S. which have significant mineral deposits often create a state mineral, rock, stone or gemstone to promote interest in their natural resources, history, tourism, etc. Not every state has an official state mineral, rock, stone and/or gemstone, however.
Jasper, an aggregate of microgranular quartz and/or cryptocrystalline chalcedony and other mineral phases, [1][2] is an opaque, [3] impure variety of silica, usually red, yellow, brown or green in color; and rarely blue. The common red color is due to iron (III) inclusions. Jasper breaks with a smooth surface and is used for ornamentation or as ...
Serpentine subgroup is a set of common rock -forming hydrous magnesium iron phyllosilicate ((Mg, Fe)3 Si 2 O 5(OH)4) minerals, resulting from the metamorphism of the minerals that are contained in mafic to ultramafic rocks. [ 6 ] They may contain minor amounts of other elements including chromium, manganese, cobalt or nickel.
Greenschist. Greenschists are metamorphic rocks that formed under the lowest temperatures and pressures usually produced by regional metamorphism, typically 300–450 °C (570–840 °F) and 2–10 kilobars (29,000–145,000 psi). [1] Greenschists commonly have an abundance of green minerals such as chlorite, serpentine, and epidote, and platy ...
Prasiolite (also known as green quartz, green amethyst or vermarine) is a green variety of quartz. Since 1950, almost all natural prasiolite has come from a small Brazilian mine, [citation needed] but it has also been mined in the Lower Silesia region of Poland. Naturally occurring prasiolite has also been found in the Thunder Bay area of Canada.
Claystone – Clastic sedimentary rock composed primarily of clay-sized particles. Coal – Combustible sedimentary rock composed primarily of carbon. Conglomerate – Sedimentary rock composed of smaller rock fragments. Coquina – Sedimentary rock that is composed mostly of fragments of shells.
Jadeite is a pyroxene mineral with composition Na Al Si 2 O 6. It is hard (Mohs hardness of about 6.5 to 7.0), very tough, and dense, with a specific gravity of about 3.4. It is found in a wide range of colors, but is most often found in shades of green or white. Jadeite is formed only in the subduction zones of continental margins, where rock ...
Chlorite group. Monoclinic 2/m; with some triclinic polymorphs. Various shades of green; rarely yellow, red, or white. Foliated masses, scaley aggregates, disseminated flakes. The chlorites are the group of phyllosilicate minerals common in low-grade metamorphic rocks and in altered igneous rocks. Greenschist, formed by metamorphism of basalt ...