|
Hard- ness |
Cleavage |
Fracture |
Trans- parency |
10% HCl Reaction |
SG |
Luster |
Color |
Streak |
Xtal Form |
Mineral Class |
Comments | amethyst (quartz) | 7.00 | none | conchoidal | Transparent | none | 2.65 | glassy | purple | white | prismatic | silicates | Purple color due inclusion of iron in crystal structure. Can be changed to citrine by heating. |
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