ROCKHOUNDING CALIFORNIA

Notes

There’s still gold in the Golden State. Though gone are the days when miners could pluck gold from the surface of the ground, gold flakes and nuggets can still be found in rivers and streams. All you need to start your search is a gold pan and, as always, awareness of local laws and land ownership.

Gold can be found throughout California, but Northern California has long been the best place to look. Try your luck searching in Marshall Gold Discovery State Park, where James W. Marshall's discovery in 1848 sparked the California Gold Rush. For locations closer to home, check out our map.

Notes

After the Gold Rush, miners searching for gold in San Diego County came across another valuable mineral: tourmaline.

Tourmaline (tor·muh·leen) is a gemstone that occurs in every shade of the rainbow. Some tourmaline, like watermelon tourmaline, even have multiple colors within the same stone. Though the mineral’s color may change, the shape stays the same: a slender, elongated crystal with grooves on the side.

The easiest way to find gem-quality tourmaline is by visiting the tourmaline mines in San Diego County. There, you can sift through material removed from the mines in search of the colorful gemstone. You may even find the famous hot-pink tourmaline that the Dowager Empress of China loved.

Notes

Blueschist (blue·shist) is rare because it requires relatively unique conditions to form: low temperatures, high pressure and rocks rich in iron or magnesium.

One of the best places to collect blueschist is at Two Harbors Beach on Catalina Island. Look along the shoreline for the ocean-washed blue and green pebbles.

Much of the northwest half of the island is composed of blueschist, greenschist and amphibolite rocks. Be sure to only look though — most of Catalina Island does not allow rock collecting.

Notes

Benitoite, California’s official state gem, was discovered in 1906 by J.M. Couch in San Benito County. The deep blue crystal was originally thought to be a sapphire but was declared a new mineral in 1907 and named after the area where it was first found.

Benitoite (beh·nee·tow·ait) forms as crystals in areas with blueschist and serpentine. The crystals are often triangular and occur mostly in shades of blue, white and sometimes pink. The gem also fluoresces under ultraviolet light.

The only place where you can find gemstone-quality benitoite is the Benitoite Gem mine, a 90-minute drive southwest of Fresno. Search through dirt brought up from the mine and you might walk away with something good.

Notes

Anorthosite (an·awr·thuh·sahyt) is most well-known for being the rock found on the brighter parts of the moon, known as the lunar highlands. Anorthosite results from melting of mantle rocks. The version of anorthosite found on the moon was formed from the Lunar Magma Ocean, a layer of molten rock present on the surface of the moon during the moon’s initial development.

The anorthosite that you can find in Southern California formed in a similar way. These rocks are 1.3 billion years old and were created by the molten portion of the Earth's mantle below the San Gabriel Mountains during that time.

Notes

Agate (ag·it) is abundant throughout Southern California and comes in a variety of colors and patterns. It is typically formed within volcanic and metamorphic rocks and consists of mostly chalcedony and quartz.

Agate is a hard mineral with a waxy surface. Though it can be difficult to identify because of the range of colors it comes in, agate is typically translucent and will allow light to pass through it.

The beach is a great place to find and collect agate. Beach agate is often smooth and may contain a banding pattern. On a sunny day, you may be able to distinguish beach agate from other stones by looking for the pebbles that seem to glow in the light. Agate found in other areas, such as the desert, is more likely to contain patterns like lace, moss or banding.