How to identify Shungite

To correctly identify Shungite (Carbonaceous rock), 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

   Typically dull black to silvery-black.

2. 2

   Luster

   How the surface reflects light: metallic, vitreous, dull

   Ranges from dull, earthy to sub-metallic or vitreous, depending on the carbon content and purity.

3. 3

   Texture

   Grain size and surface feel: coarse, fine, glassy

   Can be massive, compact, or porous. Higher carbon content varieties tend to be more homogeneous and dense. Fracture surfaces are typically conchoidal to uneven.

4. 4

   Crystal Form

   Shape of visible crystals or crystal faces

   Amorphous to cryptocrystalline; it does not form macroscopic crystals. Carbon is present as disordered, non-graphitic structures.

5. 5

   Cleavage

   How it breaks: flat cleavage planes vs irregular fracture

   None. It exhibits fracture.

6. 6

   Geological Environment

   The rock formation and setting where it occurs

   Found in ancient Precambrian sedimentary basins that have undergone low-grade metamorphism, typically associated with black shales, schists, and other carbon-rich metasediments. The primary deposit is in the Shunga region of Karelia, Russia.

Key Facts

Hardness

3-4 on the Mohs scale

Specific Gravity

1.8-2.1 g/cm³ (varies with carbon content and impurities)

Crystal System

Amorphous to cryptocrystalline (no defined crystal system)

Color

Black, sometimes with a silvery sheen

Luster

Dull, earthy, sub-metallic, or vitreous

Transparency

Opaque

Fracture

Conchoidal to uneven

Cleavage

None

Composition

Primarily carbon (C), with varying amounts of silicates (SiO2, Al2O3, Fe2O3, MgO, K2O, etc.) and other trace elements. Carbon content can range from <10% to >98%.

Physical characteristics

• Crystal Habit: Massive, compact, or porous aggregates; no distinct crystal forms.
• Cleavage Type: Absent
• Fracture Type: Conchoidal to uneven, sometimes splintery in lower-grade varieties.
• Tenacity: Brittle
• Luster Type: Dull, earthy, sub-metallic, or vitreous

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