Mechanical
|
| Density: |
Gr./Cu. Cm. · 2.6-3.2
Lb./Cu. Ft. · 160-200 |
| Hardness, Mohs |
2.0-3.2 |
| Cleavage |
Basal, Eminent |
| Crystal Structure |
Monoclinic |
| Max. Temperature with no decomposition |
400-500°C |
| Specific heat (25°C) |
.206-.209 |
| Thermal Conductivity perpendicular to cleavage: |
Cal./Sq. Cm./Sec./Cm./°C · 16x10-4
B.T.U./Sq. Ft./Hr./I.°F · 4.6 |
| Coefficient of expansion per °C perpendicular to cleavage: |
20° - 100° C · 15x10-6 - 25x10-6
100° - 300° C · 15x10-6 - 25x10-6
300° - 600° C · 16x10-6 - 36x10-6 |
| Coefficient of expansion per °C parallel to cleavage: |
0° - 200° C · 8x10-6 -
9x10-6
200° - 500° C · 10x10-6 - 12x10-6 |
| Tensile strength, P.S.I. |
37,000 - 43,000 |
| Modulus of elasticity |
25x106 |
Electrical
|
| Dielectric Constant |
6.5 - 9 |
| Dielectric Strength (highest qualities 1-3 mils thick), olts/Mil. |
6,000 - 3,000 |
| Power Factor at 25°C (77°F) (highest qualities), percent: |
60 cycles · 0.08 - 0.09
1 megacycle · 0.01 - 0.02 |
| Resistivity, Ohm-Cm. |
1012 - 1015 |
Optical
|
| Optic axial angle (2V) degrees |
38 - 47 |
| Orientation of optic plane to plane of symmetry |
Perpendicular |
| Indexes of refraction |
Alfa · 1.552 - 1.570
ß · 1.582 - 1.607
Char · 1.588 - 1.611 |
