Geology Reference
In-Depth Information
Table 10.1
Characteristics of common metalliferous minerals found in association with igneous intrusions.
Mineral
Chemical Usual colour
Lustre
Usual form
Hardness
Density
(
×
10
-3
kg m
-3
)
formula
and streak
Chalcopyrite CuFeS
2
Brass yellow to golden
yellow, sometimes
irridescent tarnish; black
streak
Metallic
Usually occurs as vein
encrustations,
occasional small cubic
crystals
3.5-4.0
4.1-4.3
Pyrite
FeS
2
Pale brass yellow to
bronze yellow;
greenish-black streak
Metallic
Smooth, shiny or
striated crystals, often
forms good cubes
6.0-6.5
5.0-5.2
Arsenopyrite FeAsS
Silver grey to steel grey;
black streak
Metallic, steely
Massive, occasionally
radiating clusters
5.5-6.0
5.9-6.2
