5.2" Marcasite, Tabular Barite and Quartz Association - Morocco

This specimen contains an association marcasite, quartz and tabular yellow barite. The marcasite has a beautiful luster to it, as well as a wonderful clustered crystal structure. Very small amounts of chalcopyrite and pyrite can be found peppered throughout this specimen. The chalcopyrite can be noted by its brassy yellow coloration and spots of green copper oxidation.

Barite, commonly spelled baryte, is well-known for its great range of colors and varied crystal forms and habits. = It is a heavy mineral consisting of barium sulfate, and typically has the chemical formula of BaSO4. The barite group consists of baryte, celestine, anglesite, and anhydrite. It is generally white to colorless and is the main source of barium.

Quartz is the name given to silicon dioxide (SiO2) and is the second most abundant mineral in the Earth's crust. Quartz crystals generally grow in silica-rich environments--usually igneous rocks or hydrothermal environments like geothermal waters--at temperatures between 100°C and 450°C, and usually under very high pressure. In either case, crystals will precipitate as temperatures cool, just as ice gradually forms when water freezes. Quartz veins are formed when open fissures are filled with hot water during the closing stages of mountain formation: these veins can be hundreds of millions of years old.

Chalcopyrite is a brass-yellow colored mineral and an important copper ore. When weathered, chalcopyrite loses its metallic luster, turning a gray-green color. When exposed to acids, the tarnish can develop a red, blue, or purple iridescence: this acid-treated material is often sold under the name peacock ore.

Marcasite, Quartz & Barite
Bou Nahas Mine, Oumjrane area, Morocco
5.2 x 4.1"