Graphite

If it’s dark grey or black, quite soft, and prone to leaving schmutz all over everything, it’s graphite.

Physical Properties
Chemical formula C
Class Native element
Crystal system Hexagonal (rhombohdral)
Habit Hexagonal tablets
Foliated and scaly masses
Radiating or granular aggregates
Color Lead grey
Black
Hardness 1 to 2
Specific gravity 2.1 to 2.2
Cleavage Perfect basal (001)
Fracture Elastic
Flexible
Luster Submetallic
Transparency Opaque
Streak Black
after Perkins, 354

Graphite in Hand Sample

Small graphite sample

Scanning electron micrograph of graphite

Graphite in Thin Section

Thin Section GigaPans

Graphite in graphite schist, plane polars

Graphite in graphite schist, crossed polars

Graphite schist, plane polars
Graphite schist, plane polars

Graphite schist, crossed polars
Graphite schist, crossed polars

Further Reading

Graphite at webmineral.com

Graphite at mindat.org