Quartz (iron-coated) with Dolomite and Calcite

Quartz – SiO₂

Elements: Silicon, Oxygen

Class: Silicates – Tectosilicates

Crystal System: Hexagonal

Hardness: 7

Quartz

Talc (1)Diamond (10)

Very hard. Scratches glass and steel.

Dolomite – CaMg(CO₃)₂

Elements: Calcium, Magnesium, Carbon, Oxygen

Class: Carbonates

Crystal System: Hexagonal

Hardness: 3.5-4

Fluorite

Talc (1)Diamond (10)

Softer than glass. A steel knife scratches it.

Calcite – Ca(CO₃)

Elements: Calcium, Carbon, Oxygen

Class: Carbonates

Crystal System: Hexagonal

Hardness: 3

Calcite

Talc (1)Diamond (10)

A copper coin can scratch it.

Size: 17.1 x 6.8 x 4.2 cm Origin: Fengjiashan Mine, Daye Co., Huangshi Prefecture, Hubei Province – China

More minerals containing Carbon