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Gems and minerals are found right here in San Diego County. From the desert to the mountains and all the way to the coast, hidden mines can yield valuable treasures. Even on the bare ground you can find sparkly stones. The Nat’s gems and minerals have been stored in the Museum’s collection for decades, but a brand new exhibition opening this November will bring them back to light.

The Museum maintains an extensive collection of minerals from Southern California, as well as a synoptic collection of minerals from around the world, including 26,000 catalogued specimens of minerals, meteorites, and precious gems. Of particular interest is the collection of valuable minerals found in pegmatite deposits in San Diego County, including extensive tourmaline deposits.

Minerals are big here!

Picture a mass of hot molten magma spreading below the Earth’s surface. As it cools slowly into solid rock, steam concentrates into trapped pockets that cool slowly over millennia. Geologists know these pockets are where to find amazing minerals such as tourmaline, topaz, and beryl, as well as common ones like quartz, and mica. More.

What about rocks?

Are rocks and minerals the same thing? What is a meteorite? How about geodes? So many questions! Earth’s crust is made up of rocks that are changing all the time. More.

Gold, you say?

Of course! This is California, after all. Yes, gold deposits are here San Diego County, and have been mined as far back as 1869. Most mines here are now too dangerous to enter and are closed permanently, but you can still look for gold in a few places such as in Julian and Pala. More.

San Diego on the move

The complex geologic history of our region makes San Diego County mineral-rich and its terrain incredibly diverse. Plate tectonics and earthquakes play a big part in that story. More.