mineral

Fluorite

Calcium Fluoride (CaF2)

Hardness: 4 on Mohs scale; Color: Green, purple, and white (variegated); Luster: Vitreous (glassy); Crystal Structure: Isometric; Cleavage: Perfect octahedral; Specific Gravity: 3.18

Hardness: 4 on Mohs scale
Color: Green, purple, and white (variegated)
Luster: Vitreous (glassy)

Identified July 21, 2026More mineral →

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Physical properties

Hardness: 4 on Mohs scale; Color: Green, purple, and white (variegated); Luster: Vitreous (glassy); Crystal Structure: Isometric; Cleavage: Perfect octahedral; Specific Gravity: 3.18

Formation & geological history

Commonly formed in hydrothermal veins, often as a gangue mineral alongside metallic ores. It can also be found in vugs within limestones and dolomites. Formation can occur across various geological ages from Precambrian to recent periods.

Uses & applications

Used as a flux in steel making and aluminum smelting. Also used in the manufacture of high-clarity lenses for cameras and telescopes, as a source for fluorine in chemicals, and as a popular ornamental and carving material.

Geological facts

Fluorite is the origin mineral for the term 'fluorescence' because many specimens glow under ultraviolet light. It is also known as 'Blue John' when referring to a famous banded variety found in Derbyshire, England.

Field identification & locations

Identify in the field by its distinct four directions of perfect cleavage and lower hardness (it can be scratched by a steel knife). Look for its characteristic isometric (cubic or octahedral) crystal habits in hydrothermal deposit areas. Found globally, with major deposits in China, Mexico, South Africa, and the USA.