Environmental Engineering Reference
In-Depth Information
Plagioclase feldspar
Nonmetallic light
White, blue gray
6-6.5
2.5
Cleavage in two directions.
NaAlSi
3
O
8
to CaAl
2
Si
2
O
8
color
Striations on some cleavage planes
Quartz
Nonmetallic light
Various
7
2.65
Conchoidal fracture, six-sided
SiO
2
(silica)
color (vitreous)
crystals, transparent to translucent
Cryptocrystalline
Nonmetallic (dull or
Various
6-6.5
Translucent to opaque. No cleavage
Quartz SiO
2
clouded)
(banded)
(Agate)
(dark)
(Flint)
(light)
(Chert)
(red)
(Jasper)
(Opal)
(waxy)
(light)
Halite
Nonmetallic
Colorless to white
2-2.5
2
Perfect cubic cleavage. Soluble
NaCl
in water. Salty
Gypsum
Nonmetallic
White
2
2.3
Perfect cleavage in one direction.
CaSO
4
⋅
2H
2
O
Transparent
Many varieties
Calcite
Nonmetallic
White or pale yellow
3
2.7
Perfect cleavage in three directions
CaCO
3
or colorless
. Transparent to opaque
Effervesces in HCl
75
Dolomite
Nonmetallic
Variable, commonly
3.5-4
2.8
Cleavage as in calcite. Effervesces in
CaMg(CO
3
)
2
white, pink
HCl only when powdered
Fluorite
Nonmetallic
Colorless, blue, green,
4
3
Good cleavage in four directions.
CaF
2
yellow, violet
Cubic crystals. Transparent to
translucent
Muscovite (see
Table 5.2)
Nonmetallic
Colorless in thin
2-3
2.8
Perfect cleavage one direction,
sheets
producing thin elastic sheets
Talc
Nonmetallic (pearly)
Green to white
1
2.8
Soapy feed, foliated or compact
KAl
2
(AlSi
3
O
10
)(OH)
2
masses
Kaolinite
Nonmetallic (earthy)
White to red
1.2
No cleavage visible
Al
4
Si
4
O
10
(OH)
8
Plastic when wet
Nephelite
Vitreous to greasy
Various
5-6
2.6
Conchoidal fracture (also nepheline)
Na
8
K
2
Al
8
Si
9
O
34
a
After Hamlin, W.K. and Howard, J.L.,
Physical Geology Laboratory Manual
, Burgess Pub. Co., Minneapolis, 1971.
