Thursday, October 31, 2013

Gemstone of the Week: (Black) Obsidian



(Image of Obsidian found on newark.osu.edu)

Obsidian is a beautiful igneous rock and is actually a naturally occurring glass. I don't think it is really known when Obsidian was first discovered, but according to one site that I looked at, the stone was named after a man named Obsius who is purported to have discovered it in Ethiopia. Obsidian has a hardness of about 5.5-6 and can be used to make absolutely beautiful jewelry. Being a natural glass, it has a vitreous luster and may be either transparent or translucent.  Most often when thinking of Obsidian, one associates it as being a black stone.  And it can be, however, there are many, many different varieties of Obsidian available.  Obsidian may be black, bluish, green, brown, and red.  Then there are the more interesting varieties of Obsidian such as: "snowflake", "fire", "rainbow," "gold sheen," "silver sheen," and "mahogany." Each of these more unusual varieties of Obsidian I will post about in separate blog posts.  Obsidian may be found in: Antarctica, Argentina, Armenia, Bolivia, China, Ethiopia, Georgia, Greece, Iceland, Italy, Japan, Madagascar, Mexico, New Zealand, Peru, Poland, Slovakia, Turkey, and the states of: Arizona, California, Colorado, Hawaii, Idaho, Nevada, New Mexico, Oregon, Utah, and Wyoming.