"A"
Gemstone |
Crystal System |
Density |
Hardness |
Refractive index |
Treatments |
|
trigonal |
3.06 |
7.0-7.5 |
1.624-1.644 |
none known |
|
monolinic |
3.00 |
5-6 |
1.602-1.655 |
none known |
|
orthorhombic |
4.32-4.68 |
3.5 |
1.710-1.768 |
none known |
|
microcrystalline |
2.66 |
6.5-7.0 |
1.544-1.553 |
dying |
|
hexagonal |
2.55-2.65 |
5.5-6.0 |
1.523-1.529 |
one known |
|
triclinic |
2.96 |
3.5 |
1.550-1.641 |
none known |
|
orthorhombic |
3.72 |
8.5 |
1.746-1.755 |
none known |
Allanite
|
monoclinic |
3.40-4.20 |
6-7 |
1.640-1.828 |
none known |
|
triclinic |
2.57-2.77 |
6.0-7.0 |
1.527-1.590 |
none known |
|
triclinic |
2.56 |
7.0-7.5 |
1.522-1.530 |
none known |
Amber
|
amorphous |
1.08 |
2.0-2.5 |
1.54 |
heating, oiling, reconstitution |
Amblygonite
|
triclinic |
2.9-3.11 |
5.5-6.0 |
1.578-1.636 |
none known |
Amethyst
|
hexagonal |
2.66 |
7 |
1.544-1.553 |
heating alters to citrine |
Ametrine
|
hexagonal |
2.66 |
7 |
1.544-1.553 |
none known |
Ammolite
|
Aggregate |
2.60-2.85 |
4.5-5.5 |
1.520-1.680 |
Opticon, Coating |
Anatase
|
tetragonal |
3.82-3.97 |
5.5-6.0 |
2.488-2.564 |
none known |
Andalusite
|
orthorhombic |
3.2 |
7.5 |
1.63-1.64 |
none known |
Andesine
|
triclinic |
2.66 |
6.0-6.5 |
1.542-1.562 |
diffused |
Apatite
|
hexagonal |
3.2 |
5 |
1.63-1.64 |
heat |
Apophyllite
|
tetragonal |
2.40 |
4.5-5.0 |
1.535-1.537 |
none known |
Aquamarine
|
hexagonal |
2.72 |
7.5-8.0 |
1.577-1.583 |
heat |
Axinite
|
Triclinic |
3.28 |
6.5-7.0 |
1.674-1.706 |
none known |
Azurite
|
monoclinic |
3.7-3.8 |
3.5-4.0 |
1.730-1.838 |
none known |
|