Agate
This is a semi-pellucid variety of quartz. The colours are arraigned
in strips or bands or blended in clouds and classified accordingly as
moss, ribbon, dendrite, etc. The stone, widely distributed but not
very popular, is generally brown. When used for ornamental purposes it
has usually been dyed artificially as the porous nature of this
mineral allows it to absorb material from solution. Brownish- orange
agate is known as cornelian, the green variety chrysoprase, the blue
variety chalcedony and the brownish-red variety carnelian. Black agate
is onyx.
Agate is used for inexpensive jewelry, ornaments and even ash- trays
and precision instruments.
It is found mainly in India, Brazil, Madagascar, China, Russia and
Australia.
|
Name |
|
|
|
|
|
|
|
|
|
| Agate (Quartz) |
6.5+ |
2.60-2.65 |
Hexagonal |
None |
1.54-1.55 |
up to 0.006 |
0.013 |
None |
Variable |
|
