|
Characteristic
|
Unit
|
Muscovite
|
Phlogopite
|
|
Colour
|
|
Ruby
/ Green
|
Amber
/ Yellow
|
|
Density
|
gm/cm3
|
2.6
- 3.2
|
2.6
- 3.2
|
|
lb/ln3
|
0.095-0.116
|
0.095-0.116
|
|
Specific
Heat
|
|
0.21
|
0.21
|
|
Hardness
|
Moh
Scale
|
2.8
- 3.2
|
2.3
- 3.0
|
|
Shore
Test
|
80
- 105
|
70
- 100
|
|
Optic
Axial Angle
|
|
55
- 75
|
5
- 25
|
|
Tensile
Strength
|
kgf/cm2
|
about
1750
|
about
1000
|
|
lbf/in2
|
about
25000
|
about
15000
|
|
Shear
Strength
|
kgf/cm2
|
2200
- 2700
|
1000
- 1300
|
|
lbf/in2
|
31000
- 38000
|
14000
- 19000
|
|
Compression
Strength
|
kgf/cm2
|
1900
- 2850
|
---
|
|
lbf/in2
|
27000
- 32000
|
---
|
|
Modulus
of Elasticity
|
kgf/cm2
x 10-3
|
1400
- 2100
|
1400
- 2100
|
|
lbf/in2
X 10-6
|
20
- 30
|
20
-30
|
|
Coefficient
of expansion per ° C perpendicular to cleavage plane
|
|
9
X 10-6 - 36 X 10-6
|
30
X 10-6 - 60 X 10-6
|
|
Calcining
Temperature
|
C
|
700
- 800
|
900
- 1000
|
|
F
|
1290
- 1470
|
1650
-1830
|
|
Maximum
operating temperature
|
C
|
500
- 600
|
800
- 900
|
|
F
|
930
- 1110
|
1470
-1650
|
|
Thermal
conductivity
|
|
|
|
|
Perpendicular
to cleavage planes
|
Gm.cal/sec/cm2/C/cm
|
about
0.0013
|
about
0.0001
|
|
BTU/hr/ft2/0f/ft
|
about
0.31
|
about
0.24
|
|
Parallel
to cleavage planes
|
Gm.cal/sec/cm2/C/cm
|
|
about
0.012
|
|
BTU/hr/ft2/0f/ft
|
|
about
3.0
|
|
Water
of constitution %
|
|
4.5
|
3.0
|
|
Moisture
absorption
|
|
Very
low
|
Very
low
|
|
Apparent
electric strength
|
0.001"
to 0.003" KV/mm
|
120
- 200
|
---
|
|
thick
Volts per 0.001"
|
3000
- 5000
|
---
|
|
R.M.S.
at 15° C (60°F)
|
0.01"
to 0.05" KV/mm
|
40
- 80
|
30
-60
|
|
thick
Volts per 0.001"
|
1000
- 2000
|
750
-1500
|
|
Permittivity
at 15°C(60oF)
|
|
6
- 7
|
5
- 6
|
|
Power
Factor (loss tangent)
|
@
15° C (60° F)
|
0.0001
- 0.0004
|
0.001
- 0.005
|
|
Volume
Resistivity
|
25°
C (77° F) ohm cm
|
40
x 1013-2 x 1017
|
1
x 1012 - 1 x 1012
|
|
Acid
reaction
|
|
Affected
by Hydrofluoric Acid
|
Affected
by Sulphuric Acid
|