Almost 30 million years ago, an asteroid or comet impact fused Saharan quartz grains into desert glass.
Category: Ooh . . . Shiny!
Guest Video: Collecting Topaz in Utah
Topaz is the hardest silicon-based mineral, and its clarity and beautiful color make this a beautiful and very popular gemstone. Topaz got its name from
Guest Videos: The Hidden Secrets of Minerals
Air bubbles and other meterial trapped in mineral grains tell scientists many things about the Earth and its history.
Guest Video: Microphotographs of Gemstones
Microphotgraphy using polarized light yields beautiful art. It also is very helpful in learning more about a gem.
Guest Video: What’s Cooking? Montana Sapphires!
We’ve looked before at how sapphires for. Now let’s check out Montana sapphires – North America’s biggest known deposit of gem-quality stones – and see how gemologists manage to get every bit of color they possibly can from each sapphire – even the green ones!
Guest Video: Peridot, A Mantle Gem
Diamonds aren’t the only mantle-associated gems. Most of the upper mantle is made out of peridotite, a combination of olivine and pyroxene. It is named after the very famous gemstone it contains–peridot.
