Economic Minerals

Pyrite Colour

Pale-brass yellow

Pyrite key characteristics
Lustre, form, streak, fracture, cleavage, hardness, specific gravity

Metallic Lustre
Cubic form
Greenish/brownish black streak
Uneven or irregular fracture
No cleavage
Hardness of 6-6.5
Specific gravity 4.95-5.10

Molybedenite Colour

Lead-silvery grey

Molybdenite Key Characteristics
Lustre/feel, form, streak, fracture, cleavage, hardness, specific gravity

Metallic but has a soft and greasy feel
Thin, platy hexagonal crystals
Bluish grey streak
Sectile fracture (thin curved shavings)
One perfect cleavage
Hardness of 1-1.5 (can be scratched by a finger nail)
Specific gravity of 4.73

Sphalerite Colours

Range of colours including light to dark brown, red-brown, yellow, red, green, light blue, black and colorless

Sphalerite Key characteristics
Lustre, form, streak, fracture, cleavage, hardness, specific gravity

Adamantine, resinous, greasy lustre
Tetrahedral or dodecahedral form
Brownish white, pale yellow streak
Uneven to conchoidal fracture
6 perfect cleavage planes
Hardness of 3.5-4
Specific gravity of 3.9-4.2

Galena
Lustre, form, streak, fracture, cleavage, hardness, specific gravity

Metallic lustre
Cubes and octahedral form
Lead grey
Subconchoidal fracture
3 perfect cleavage planes
2.5-2.75 hardness
7.2-7.6 specific gravity