|
Mineralogy :
|
| Tradename(s) |
Flame,
Fire, Plume, Graveyard, Lace and many
others. |
| Family |
Chalcedony /
Quartz |
| Description |
Agate is a
generic term for all microcrystalline
variety of quartz of many colors Also known as chalcedony or
chalcedonic quartz, Agate forms when
silicated rich water seeps into crevices and
becomes trapped by cooling magma. It also
occurs as spherical or almond shaped nodules
in volcanic rocks. The banding is the result
of rhythmic crystallization. Frequently in
the center of the almond shaped rock are
well developed crystals. Colors vary but
the most common are varying shades of grey.
There are numerous varieties of agate. |
| Mohs |
6.5-7 |
| Chemical
Composition |
SiO2 |
| Refractive
Index |
|
| Specific
Gravity |
2.58 -
2.64 |
| Cleavage |
none |
| Streak |
White |
| Localities |
World-wide, most notable are Brazil, Uruguay, China,
India, Madagascar, Mexico, and U.S.A. |