2" Roselite, Quartz and Calcite Association - Morocco

 
This is a unique crystal association collected from the Bou Azer District of Morocco. The deepest red coloration is a result of roselite crystals. Above that is a formation of calcite (cobaltoan calcite) that took on the magenta coloration as a result of impurities from the cobalt content within the surrounding rock. Small microscopic quartz crystals can be found peppered across the calcite.

Roselite is a monoclinic mineral of the hydrated phosphates group, and has a chemical formula of Ca2Co(AsO4)2 · 2H2O. It gained its name not from the rose color that is generally exhibited by the mineral, but was in fact named in honor of a German mineralogist by the name of Gustav Rose. However, the name is quite fitting, for roselite typically displays a vitreous rose-red to pink color. Darker colored crystals have been known to frequently display marked color zoning due to variations in molecular composition.

Calcite, CaCO3, is a carbonate mineral and the most stable polymorph of calcium carbonate. The other polymorphs are the minerals aragonite and vaterite. Calcite crystals are trigonal-rhombohedral, though actual calcite rhombohedra are rare as natural crystals. However, they show a remarkable variety of habits including acute to obtuse rhombohedra, tabular forms, and prisms. Calcite exhibits several twinning types adding to the variety of observed forms. It may occur as fibrous, granular, lamellar, or compact. Cleavage is usually in three directions parallel to the rhombohedron form.

Cobaltoan calcite, also known as cobaltocalcite, is one of many different varieties of calcite, forming with a chemical composition of (Ca,Co)CO3. It crystallizes in a trigonal crystal system and forms rhombohedral or scalenohedral crystals. These crystals tend to display a pink color of which intensity can range anywhere from a pinkish-salmon to a hot pink.

Silicon Dioxide, also know as SiO2 or Quartz, is the second most abundant mineral in the Earth's crust. Quartz crystals generally grow in silica-rich, hot watery solutions called hydrothermal environments, at temperatures between 100°C and 450°C, and usually under very high pressure. Quartz veins are formed when open fissures are filled with hot water during the closing stages of mountains forming, and can be hundreds of millions of years old.
DETAILS
SPECIES
Roselite, Quartz & Calcite
LOCATION
Bou Azer District, Morocco
SIZE
2 x 1.6"
SUB CATEGORY
ITEM
#137024