| Kyanite
is a mineral infrequently cut as
a gemstone. It occurs in light to
dark blue, green, colorless and
brown colors in a transparent form
with the blue color being most used
in gemstones. Kyanite is of interest
because of the extreme variablity
in hardness with direction. In one
direction, the hardness is 4.5 and
in the other it is 7. Very easy
cleavage is encountered in one direction
with a less perfect cleavage occurring
at 74 degrees to the first. The
finest gem quality Kyanite may be
confused in appearance with spinel
or blue sapphires from Burma.
|
| Gemological
Information |
| Color
: |
Blue,
Greenish Blue. |
| Refractive
Index: |
1.716
– 1.731 |
| Chemical
Composition: |
AL2SIO5 |
| Hardness: |
4.5
– 7.0 |
| Density: |
3.56
– 3.68 |
| Crystal
Group: |
Triclinic |
| Ocurrence: |
Kenya,
Nepal, India, Burma,U.S.A. |
|
|
|
