Quartz comes in a great many different forms and colors, some of them incredibly beautiful

Here are a few more of the rocks and minerals I found on display in the Mining and Ranching building of the Angels Camp Museum.

Borates are crystallized salts that contain boron. They are used in many different applications, from fertilizing plants to forming heat-resistant glass and fiberglass insulation. They’re most heavily concentrated in dry, waterless environments like California’s Mojave Desert or the Atacama in Chile.

Although has been designated California’s state rock, serpentine is actually not a specific type of rock but a group of minerals with the same general formula. Usually green or brown in color, these serpentine minerals come in a number of different forms; the chrysolite form has been an important source of asbestos in the past.

Malachite and azurite are both copper-based gemstones — malachite is green while azurite, as you may have guessed from the name, is deep blue. Both have been known and used since ancient times; malachite was already being mined and smelted to produce copper over 3,000 years ago. They were also both used as pigments in their respective colors.

Chrysolla, or chrysocolla, is another copper-based mineral, blue-green in color; as a gemstone, it’s often mistaken for turquoise. It’s also the national stone of Israel. In ancient times it was used as  solder to weld gold pieces together, giving rise to its name which is Greek for “gold glue.”

I have one final installment of minerals, coming soon!