Fluorite “Ice Cubes”, Galena & Quartz

Fluorite – CaF₂

Elements: Calcium, Fluorine

Class: Halides

Crystal System: Cubic

Hardness: 4

Fluorite

Talc (1)Diamond (10)

Softer than glass. A steel knife scratches it.

Galena – PbS

Elements: Lead, Sulfur

Class: Sulfides

Crystal System: Cubic

Hardness: 2.5-2.75

Calcite

Talc (1)Diamond (10)

Soft. A fingernail can scratch it.

Quartz – SiO₂

Elements: Silicon, Oxygen

Class: Silicates – Tectosilicates

Crystal System: Hexagonal

Hardness: 7

Quartz

Talc (1)Diamond (10)

Very hard. Scratches glass and steel.

Origin: Dalnegorsk – Russia

More Sulfides