Environmental Engineering Reference
In-Depth Information
TABLE 5.5
Characteristics of Some Common Minerals
a
Mineral
Streak
Luster
Color
Hardness
Specific
Characteristics
Gravity
Galena PbS
Gray
Metallic
Silver-gray
2.5
7.6
Perfect cubic cleavage
Magnetite Fe
3
O
4
Black
Metallic
Black to dark gray
6
5.2
Magnetic
Graphite C
Black
Metallic
Steel gray
4
2
Greasy feel
Chalcopyrite CuFeS
2
Greenish-black
Metallic
Golden yellow
4
4.3
May tarnish purple
Pyrite FeS
2
Greenish-black
Metallic
Brass yellow
6-6.5
5
Lacks cleavage
Hematite Fe
2
O
3
Reddish-brown
Metallic
Black-dark brown
5-6.5
5
Lacks cleavage
Limonite Fe
2
O
3
⋅
H
2
O
Yellow brown
Metallic
Yellow, brown, black
5-5.5
3.5-4
Hard structureless or radial fibrous
Pyroxene group
Nonmetallic
Dark green black
6
3.5
Cleavage, 2 at 90
, prismatic
(see Table 5.2) Augite
dark color
8-sided crystals
Amphibole group (see
Nonmetallic
Dark green, black,
6
3-3.5
Cleavage, 2 at 60
and 90
Table 5.2)
Hornblende
dark color
brown
Long 6-sided crystals
Olivine (MgFe)
2
SiO
4
Nonmetallic
Olive green
6.5-7
3.5-4.5
Conchoidal fracture, transparent to
dark color (glassy)
translucent
Garnet group
Nonmetallic
Red, brown, yellow
7-7.5
3.5-4.5
Conchoidal fracture, 12-sided
(Fe, Mg, Ca, Al silicates)
dark color (glassy)
crystals
Biotite (see Table 5.2)
Nonmetallic dark color
Brown to black
2.5-3
3-3.5
1 perfect cleavage this sheets
Chlorite (hydrous Mg,
Nonmetallic dark color
Green to very dark
2-2.5
2.5-3.5
1 cleavage direction foliated or scaly
Fe, Al silicate)
green
masses
Sphalerite ZnS
Yellow brown
Nonmetallic dark color
Yellowish-brown
3.5-4
4
Cleavage 6 directions
to white
(resinous)
Hematite Fe
2
O
3
Earth
Red
Nonmetallic dark color
Red
1.5
Earthy appearance. No cleavage
variety
Limonite Fe
2
O
3
⋅
H
2
O
Yellow
Nonmetallic dark color
Yellow brown to
1.5
Compact Earth masses. No cleavage
brown
dark brown
