How to identify Fluorite

To correctly identify Fluorite (Fluorite (Calcium Fluoride, CaF2)), check each of these features in order. Many rocks and minerals look alike, so cross-reference multiple properties before deciding.

Step-by-step identification

1. 1

   Color

   Overall color and any zoning or banding

   Extremely variable: colorless, white, purple, blue, green, yellow, pink, red, brown, black. Often color-zoned.

2. 2

   Luster

   How the surface reflects light: metallic, vitreous, dull

   Vitreous (glassy).

3. 3

   Texture

   Grain size and surface feel: coarse, fine, glassy

   Smooth, often with distinct crystal faces.

4. 4

   Crystal Form

   Shape of visible crystals or crystal faces

   Cubic, octahedral, or dodecahedral crystals are common. Can also be massive, granular, or botryoidal.

5. 5

   Cleavage

   How it breaks: flat cleavage planes vs irregular fracture

   Perfect octahedral cleavage in four directions, producing characteristic triangular or diamond-shaped fragments.

6. 6

   Geological Environment

   The rock formation and setting where it occurs

   Hydrothermal veins, pegmatites, carbonatites, sedimentary rocks (as a cement or replacement mineral), and as a gangue mineral in various ore deposits.

Key Facts

Hardness

4 (Mohs scale)

Specific Gravity

3.18 g/cm

Crystal System

Isometric (cubic)

Color

Colorless, white, purple, blue, green, yellow, pink, red, brown, black; often color-zoned.

Luster

Vitreous

Transparency

Transparent to translucent

Fracture

Subconchoidal to uneven

Cleavage

Perfect octahedral in four directions {111}

Composition

Calcium Fluoride (CaF2)

Physical characteristics

• Crystal Habit: Cubic, octahedral, dodecahedral, massive, granular, botryoidal.
• Cleavage Type: Perfect octahedral {111}, meaning it breaks into fragments with eight faces.
• Fracture Type: Subconchoidal to uneven.
• Tenacity: Brittle.
• Luster Type: Vitreous (glassy).

Explore Fluorite