4.3" Cubic Blue Fluorite and Calcite on Druzy Quartz - Fluorescent!

 
This is a beautiful association of blue cubic fluorite and calcite crystals that formed on a bed of druzy quartz. This formation resembles fluorite specimens from the Zhejiang Province of China, however the specific locality within China from which the specimen was extracted, is unknown.

Under short wave UV, this specimen fluoresces two separate colors. The calcite has an orange fluorescence, while the fluorite displays a purple fluorescence.

Fluorite is a halide mineral comprised of calcium and fluorine, CaF2. The word fluorite is from the Latin fluo-, which means to flow. In 1852 fluorite gave its name to the phenomenon known as fluorescence, or the property of fluorite to glow a different color depending upon the bandwidth of the ultraviolet light it is exposed to. Fluorite occurs commonly in cubic, octahedral and dodecahedral crystals in many different colors. These colors range from colorless and completely transparent to yellow, green, blue, purple, pink or black. Purples and greens tend to be the most common colors seen.

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.

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
Fluorite, Calcite & Quartz
LOCATION
China
SIZE
Plate 4.3 x 2.5"
CATEGORY
SUB CATEGORY
ITEM
#128571