How to identify Green Fluorite with Calcite

To correctly identify Green Fluorite with Calcite (Fluorite (CaF2) and Calcite (CaCO3)), 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

   Fluorite: Typically vibrant green, but can range from pale to deep emerald green. Calcite: Usually white, colorless, or light shades of gray, yellow, or brown.

2. 2

   Luster

   How the surface reflects light: metallic, vitreous, dull

   Fluorite: Vitreous (glassy). Calcite: Vitreous to sub-vitreous, sometimes pearly on cleavage surfaces.

3. 3

   Texture

   Grain size and surface feel: coarse, fine, glassy

   Fluorite: Smooth, often with well-formed crystal faces. Calcite: Can be smooth on crystal faces, granular, or massive.

4. 4

   Crystal Form

   Shape of visible crystals or crystal faces

   Fluorite: Commonly forms cubic, octahedral, or dodecahedral crystals. Calcite: Highly variable, often rhombohedral, scalenohedral, or prismatic. Can also be massive, granular, or fibrous.

5. 5

   Cleavage

   How it breaks: flat cleavage planes vs irregular fracture

   Fluorite: Perfect octahedral cleavage in four directions. Calcite: Perfect rhombohedral cleavage in three directions.

6. 6

   Geological Environment

   The rock formation and setting where it occurs

   Hydrothermal veins, often associated with lead-zinc-silver deposits, fluorite-barite veins, and as a gangue mineral in various ore deposits. Also found in sedimentary rocks, particularly limestones and dolostones, and occasionally in igneous rocks.

Key Facts

Hardness

Fluorite: 4 (Mohs scale). Calcite: 3 (Mohs scale).

Specific Gravity

Fluorite: 3.18 (variable with impurities). Calcite: 2.71.

Crystal System

Fluorite: Isometric. Calcite: Trigonal.

Color

Green (Fluorite), White/Colorless (Calcite)

Luster

Vitreous

Transparency

Transparent to translucent (both)

Fracture

Fluorite: Subconchoidal to uneven. Calcite: Conchoidal to uneven.

Cleavage

Fluorite: Perfect octahedral (4 directions). Calcite: Perfect rhombohedral (3 directions).

Composition

Fluorite: Calcium Fluoride (CaF2). Calcite: Calcium Carbonate (CaCO3).

Physical characteristics

• Crystal Habit: Fluorite: Cubes, octahedra, dodecahedra, massive. Calcite: Rhombohedra, scalenohedra, prisms, massive, granular, fibrous.
• Cleavage Type: Fluorite: Perfect octahedral. Calcite: Perfect rhombohedral.
• Fracture Type: Fluorite: Subconchoidal to uneven. Calcite: Conchoidal to uneven.
• Tenacity: Fluorite: Brittle. Calcite: Brittle.
• Luster Type: Vitreous (glassy) for both, sometimes sub-vitreous or pearly on cleavage surfaces for calcite.

Explore Green Fluorite with Calcite