also known as volcanic glass, is a rock rather than
a mineral that is a mixture of cryptocrystalline grains
of silica minerals in a glass-like suspension. It is
produced from volcanoes when
certain types of lava cools rapidly by flowing into a body of water. Obsidian consists
mainly of silicon dioxide and is mineral-like,
but not a true mineral because it has no crystal structure
and therefore is amorphous. Otherwise, it is very similar in composition
to granite and rhyolite. It is sometimes classified
instead as a mineraloid. Most Obsidian is typically opaque
black and not desirable for
are several types of Obsidian typically offered as
gems. The most common are opaque cabochons of black,
Mahogany, Snowflake or Rainbow Obsidian. Mahogany Obsidian
has brownish red patches or swirls in black Obsidian
while Snowflake Obsidian has grayish white patches
in black Obsidian. Rainbow Obsidian has an iridescent, rainbow-like sheen.
There are also translucent Obsidian gems with white
inclusions of Cristobalite.
These are often called Cosmic Obsidian.
type of Obsidian is called "Apache
because of a legend of the Apache tribe.
The legend is that about 75 Apache
warriors and the US Cavalry fought on a mountain overlooking what is now Superior, Arizona
in the 1870s. Facing defeat, the outnumbered Apache warriors rode their
horses off the mountain to their deaths rather than be killed by the soldiers. The
wives and families of the warriors cried when they heard of the tragedy and
their tears turned to stone upon hitting the ground. Apache Tears are usually
translucent to transparent and medium brown in color.
This mysterious gem has been called many
names including Green Obsidian, African Moldavite, Tanzanian
Green Volcanic Glass and green man-made glass. One source
says the Tanzanian natives call it Obsidianite. It is
reported to be found in alluvial deposits and in a river
bed at the base of Mt. Kilamanjaro. Some say it is a
natural volcanic glass, some argue that it is man-made
glass, others claim it is of meteoric origin similar
Where ever this material comes from or however
it was formed, it is a stunning gem of the finest Tsavorite
note: "Transparent blue or green Obsidian"
A lot of gem-quality water-clear brightly colored "Obsidian" has been
offered for sale on the internet with a variety of sources listed. The material offered for sale is in
fact a man-made glass produced in places such as Indonesia and China.