Question

mineral:fluorite
chemical formula:
color(s):
mineral group:
Streak:
hardness:
luster:
specific gravity:
cleavage:
transparency:
fracture:
sources:
Important uses 1,2,3,4;

Answer 1

mineral: Fluorite

chemical formula: CaF2

color(s): wide range — purple, green, yellow, blue, colorless, pink, brown, black; often zoned/banded

mineral group: Halide minerals

Streak: white

hardness: 4 (Mohs scale)

luster: vitreous (glassy)

specific gravity: ≈3.0–3.3 (typical ≈3.18)

cleavage: perfect in four directions — octahedral cleavage

transparency: transparent to translucent

fracture: brittle; conchoidal to uneven

sources: major producers — China, Mexico, South Africa, Namibia, Spain, Russia, Canada, United States (notable localities: Hunan & Inner Mongolia in China; Chihuahua in Mexico; Illinois/Kentucky, Elmwood TN, Derbyshire/Blue John and Weardale/England; Freiberg/Germany; Okorusu/Namibia)

Important uses:
1) Flux in steelmaking and iron smelting (metallurgical-grade fluorite, “fluorspar”)
2) Chemical feedstock for production of hydrofluoric acid (HF) and fluorochemicals
3) Optical applications — high-purity fluorite crystals and elements in lenses for low dispersion (telescopes, cameras, microscopes)
4) Gem, ornamental and collector specimens (lapidary work, carved items) and use of its fluorescence in various novelty/analytical uses