A table top made of a glimmering 6ft slice of petrified tree trunk. A single quartz crystal taller than I am (and I’m tall). Geodes you can step into. These are some of the amazing things I saw during my first trip to the Tucson Gem, Mineral and Fossil Show in Arizona last February.
My friend, jeweler Melissa Booth, had been urging me to go for several years. For her it is an annual pilgrimage, and it is indeed a mecca in the world of gem and mineral buying, collecting and trading. The gem show is actually more than 40 shows sprawled throughout the city, the premier show being that of the American Gem Trade Association (AGTA). Located inside the plush convention center is a United Nations of buyers and sellers: diamond sellers from India in impeccable suits, German stone-cutters with sapphires and topaz, South Africans with pietersite (a rare form of tiger eye), the Russian “mafia” selling, well, whatever you want.
And Australian boulder opals, which completely entranced me with their irregular shapes and variety of colors: flecks of red, bright green, cobalt blue, yellows, black, pinks, creams and purples. Definitely not your grandmother’s opals (well maybe yours but not mine).
Some opal was being sold in large chunks of the rock it formed in, clearly showing its origins. Opal begins as liquid silica and flows into open cavities in the stone. When it is mined the top is cut off revealing a shimmering river of every color imaginable. Because of the liquid nature of silica, in rare instances, fossils can become “opalized”, turned into opal. In even rarer cases the internal details of the fossil are opalized as well. Opalized dinosaur teeth, bones and entire skeletons have been excavated.