FLUORITE

Fluorite (also called Fluorspar)

Fluorite is a widely occurring halide mineral composed of calcium fluoride (CaF₂). It is famous for its perfect cubic cleavage, wide range of colors, and fluorescence under ultraviolet light. In fact, the phenomenon of fluorescence was named after fluorite.

Key Properties:

• Hardness: 4 on the Mohs scale (can be scratched with a knife, but harder than calcite)

• Cleavage: Perfect octahedral (breaks into smooth, pyramid-like shapes)

• Luster: Vitreous (glassy)

• Transparency: Transparent to translucent

• Specific Gravity: 3.18 (moderately heavy for a non-metallic mineral)

Color:

Fluorite is known as "the most colorful mineral in the world." Common colors include:

• Purple, green, blue, yellow, pink, brown, and colorless

• Color zoning (bands of different colors in a single crystal) is common

• Some specimens are colorless under daylight but fluoresce brightly under UV

Special Properties:

• Fluorescence: Glows blue, violet, or green under ultraviolet light (gave name to the phenomenon)

• Thermoluminescence: Some fluorite glows when heated

• Refractive Index: Low (1.433–1.435), making it useful for certain optical lenses

Uses & Applications:

• Optics: High-quality fluorite is used in apochromatic lenses (cameras, telescopes, microscopes) to reduce color distortion

• Metallurgy: As a flux in steel and aluminum production to remove impurities

• Hydrofluoric Acid: Primary source of fluorine for making Teflon, refrigerants, and uranium enrichment

• Jewelry & Carving: Often cut into cabochons, beads, or carved into decorative objects (though relatively soft)

• Historical: Known as "fluorspar" in industrial contexts; used since ancient times in glassmaking