mineral

Fluorite with Quartz

Fluorite (CaF2) and Quartz (SiO2)

Hardness: 4 (Fluorite) and 7 (Quartz); Color: Purple, green, clear, and smoky; Luster: Vitreous; Crystal Structure: Isometric (Fluorite), Hexagonal (Quartz); Cleavage: Perfect octahedral in fluorite; Specific Gravity: 3.18 (Fluorite), 2.65 (Quartz).

Hardness: 4 (Fluorite) and 7 (Quartz)
Color: Purple, green, clear, and smoky
Luster: Vitreous

Identified June 23, 2026More mineral →

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Physical properties

Formation & geological history

Formed in hydrothermal veins at varying temperatures; often found in limestone or as a gangue mineral in metallic ore deposits. Geological ages vary significantly depending on the deposit site.

Uses & applications

Fluorite is used as a flux in steel making, in the manufacture of hydrofluoric acid, and as a decorative stone/gemstone. Quartz is used in electronics and construction.

Geological facts

Fluorite is the mineral from which the term 'fluorescence' was derived. It comes in a wider range of colors than almost any other mineral. Quartz is the second most abundant mineral in Earth's continental crust.

Field identification & locations

Identify by purple or green cubic/octahedral cleavage (Fluorite) and the ability of the harder section (Quartz) to scratch glass. Found commonly in Illinois/Kentucky (USA), China, and Mexico.

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sedimentary

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Nephrite Jade

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Mineral/Rock

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety often found as a river rock)

Metamorphic Rock

Green Apatite on Albite

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mineral