Geographic Minerals

Anyolite Minerals

Anyolite Minerals

Although anyolite is advertised as a variety of the mineral zoisite from Kenya and the Arusha Region of Tanzania, anyolite is actually a metamorphic rock composed of intergrown green zoisite, black/dark green pargasite, and ruby. A name derived from “anyoli”, the Masai word for green......

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Antozonite

Antozonite

Antozonite (historically known as Stinkspat, Stinkfluss, Stinkstein, Stinkspar and fetid fluorite) is a radioactive fluorite variety first found in Wölsendorf, Bavaria, in 1841, and named in 1862. It is a radioactive variety of fluorite, containing traces of elemental fluorine gas. When fracture.....

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Grunerite Minerals

Grunerite Minerals

Grunerite is a mineral of the amphibole group of minerals with formula Fe7Si8O22(OH)2. It is the iron endmember of the grunerite-cummingtonite series. It is not Radioactive. It forms as fibrous, columnar or massive aggregates of crystals. The crystals are monoclinic prismatic. The luster is glass.....

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Ammolite: Properties and Occurrence

Ammolite: Properties and Occurrence

Ammolite is a beautiful organic stone that’s formed from Aragonites inside the fossilized shells of Ammonites. It is made of the fossilized shells of ammonites, which in turn are composed primarily of aragonite, the same mineral contained in nacre, with a microstructure inherited from the shell.....

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Amethyst: Properties and Occurrence

Amethyst: Properties and Occurrence

Amethyst is a violet variety of quartz often used in jewelry. It is a purple variety of quartz (SiO2) and owes its violet color to irradiation, iron impurities (in some cases in conjunction with transition element impurities), and the presence of trace elements, which result in complex crystal la.....

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Amazonite: Properties and Occurrence

Amazonite: Properties and Occurrence

Amazonite (sometimes called “Amazon stone”) is a green variety of microcline feldspar. Is translucent to opaque feldspar gemstone with a pretty green color. It is the greenish variety of the mineral Microcline. Amazonite is named after the Amazon River of South America. The name is ta.....

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Alums: Properties and Uses

Alums: Properties and Uses

The alums are a class of chemical compounds. Alums are double sulfate salts, with the general formula AM(SO4)2·12H2O, where A is a monovalent cation such as potassium or ammonium and M is a trivalent metal ion such as aluminum or chromium(III). By itself, “alum” often refers to potas.....

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Amber Minerals

Amber Minerals

Amber is fossilized tree resin, which has been appreciated for its color and natural beauty since Neolithic times. Much valued from antiquity to the present as a gemstone, amber is made into a variety of decorative objects. Amber is used in jewelry. It is very light in weight which allows it to b.....

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Alexandrite

Alexandrite

Alexandrite The alexandrite variety displays a color change dependent upon the nature of ambient lighting. Alexandrite, with its chameleon-like qualities, is a rare variety of the mineral chrysoberyl. Its color can be a lovely green in daylight or fluorescent light, changing to brownish or purpli.....

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Alabaster

Alabaster

Alabaster is a mineral or rock that is soft and often used for carving, as well as being processed for plaster powder. It is compact fine-textured usually white and translucent gypsum often carved into vases and ornaments. It normally is snow-white and translucent but can be artificially dyed; it.....

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Agate: Properties and Occurrence

Agate: Properties and Occurrence

Agate is a rock consisting primarily of cryptocrystalline silica, chiefly chalcedony, alternating with microgranular quartz. It is a fine-grained variegated chalcedony having its colors arranged in stripes, blended in clouds, or showing mosslike forms. It is a very popular stone in various feng s.....

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Adamantine

Adamantine

Adamantine is a mineral, often referred to as adamantine spar. It is a silky brown form of corundum. It has a Mohs rating of 9. It comes from the Greek and Latin word Adamas which applied to substances having the hardness or luster of a diamond. Adamantine figuratively means unyielding and inflex.....

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