English: Adamite from Mexico. (photo-stacked image; field of view: ~4.8 centimeters across)

A mineral is a naturally-occurring, solid, inorganic, crystalline substance having a fairly definite chemical composition and having fairly definite physical properties. At its simplest, a mineral is a naturally-occurring solid chemical. Currently, there are about 5400 named and described minerals - about 200 of them are common and about 20 of them are very common. Mineral classification is based on anion chemistry. Major categories of minerals are: elements, sulfides, oxides, halides, carbonates, sulfates, phosphates, and silicates.

Adamite is an uncommon zinc hydroxyarsenate mineral (Zn2(AsO4)(OH)). It typically has a yellowish color (with a greenish tint), but impurities can result in other colors, for example green and purple. Most collector-grade adamite specimens come from Mexico's Ojuela Mine. Adamite in this part of the world occurs in oxidized carbonate replacement deposits. Such deposits are folded Cretaceous carbonates subsequently mineralized by hydrothermal-magmatic fluids and then subjected to near-surface oxidative weathering.

Locality: Ojuela Mine, Mapimí, northeastern Durango State, northern Mexico

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Photo gallery of adamite:

www.mindat.org/gallery.php?min=21