|
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 (60 F) |
|
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 |
