Friday, January 15, 2010
Other gem materials and minerals of Mexico
Much fine lapidary work is done with obsidian. At Teotihuacan archeological site near Mexico City there is an obsidian workshop where for the benefit of tourists the Indians fashion traditional arrow and spear heads for sale. However, some obsidian has a beautiful flow structure which is emphasized when polished into spheres and other ornaments. The varieties known as Sheen Obsidian (yellow sheen), Rainbow Obsidian (rainbow sheen) and Snowflake Obsidian are particularly striking..
The largest Mexican deposits of obsidian are near Guadalajara and have been mined for thousands of years. A recent visit to the obsidian mines and a workshop is described by John Pint, "Obsidian in Mexico", click here.
The silver mining regions that I visited north of Mexico City (Pachuca and Guanajuato to Zacatecas) are a source of many mineral specimens of interest to the collector. The gangue minerals include quartz crystals often with an amethystine base, calcite as platy rosettes (calcita en hojas) and as spiky "dog tooth spar" and massive fluorite. Silver minerals include native silver, argentite, ruby silver, and the common sulfide minerals chalcopyrite, pyrite and galena are plentiful. I was tempted to buy some colorless topaz crystals and rare danburite crystals up to 5 cm size.