"Gems seduce us with their sparkle. But did you know that every glittering ruby, sapphire, diamond, and opal has a history as old as the Earth itself? A gem isn’t just a pretty bauble—it’s a rare and wonderful by-product of the tremendous forces that have shaped our planet. Discover how the same Earth processes that build landscapes produce dazzling gemstones and precious metals—even right here in San Diego County, one of the most famous gem-producing regions in the world. The exhibition features a stunning selection of spectacular natural mineral crystals, exquisite jewelry, and works of art."
Some of the gems that have been mined in San Diego County include Watermelon Tourmaline, Quartz and Topaz. The California State Gemstone is actually Benitoite, when this stone was first discovered in 1907 it was thought to be Sapphire.
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| More information can be found here https://statesymbolsusa.org/symbol-official-item/california/state-gem-gemstone/benitoite |
Benitoite is now but all mined out usually anything you find mined in more recent years will be smaller stones, unless they are discovered in an estate collection.