San Francisco Gem and Mineral Society

04/23/2026

If you’ve been to our clubhouse, you may have seen our famous “jade train.” This old west scene was lovingly crafted by some of our members many decades ago from a colorful variety of beautiful slabs of stone. If you haven’t seen it, come to our open house next Sunday, May 3 to check it out!

04/13/2026

Our members are always making amazing things—today we're featuring an ongoing project by Dan B. Dan is crafting botanically-accurate copper roses, using a rivet to attach the petals to the sepal and natural patina to give the copper a rosy red color. Awesome work, Dan!!

02/02/2026

We’ve been a bit delinquent in posting our library feature series, but today we’re finally back. This week’s book is all about diamonds, the official gemstone of love and commitment (well, at least since De Beers started marketing them as such in the mid 20th century).

11/17/2025

A bit late for spooky season, but today's library feature is a thick (but surprisingly lightweight) tome about the abandoned mining towns of the American west. Come read all about the boomtowns that became ghost towns, from Colorado to California.

09/15/2025

This week we're featuring a chronicle of the Comstock Lode, the massive silver rush that was the source of the fortune for many of the Bay Area's most famous names (Flood, Crocker, Hearst, and more).

09/08/2025

We had a great time learning all about turquoise from Carrie Calisay Cannon!

Did you know...

Only about 5% of turquoise is gem-grade, and much of what you find on the market is reconstituted (low-grade turquoise powder mixed with resin, often with fake "matrix" added to make it look more real)?

Composite turquoise, in contrast, is considered "real" turquoise, as it's made from tiny pieces of turquoise bonded together.

Turquoise literally means "turkish," as the European traders believed the stone to originate in Turkey, but in fact it was sourced from mines in ancient Persia (modern Iran).

Many other civilizations around the world have used turquoise in their ceremonial objects, from the Mayans and Aztecs to native tribes of the western United States.

And one of the world's most productive turquoise deposits is found right here in the deserts of the American Southwest!

09/08/2025

This week's library book feature is The Kings of El Dorado, an appropriately gilded volume displaying dozens of golden objects from the pre-Columbian civilizations of South America, land of the mythical El Dorado.

09/02/2025

This week we're featuring a slim volume about one of nature's most stunning creations: opal (derived from the Sanskrit word "upala" meaning "gem").

This book is mostly about the famed opal fields of Coober Pedy, Australia, where many residents live in caves to shelter from the 120º sun!

08/24/2025

Back to our regularly-scheduled programming! This week's book feature is "The Secret Teachings of Gemcutting," gifted to us by author Justin Prim several years ago. This book walks readers through the most common cuts, with lots of useful diagrams and measurements. Check it out in our library!

08/20/2025

That's a wrap on our 90th anniversary celebration! We had a wonderful final weekend, full of rock painting, geode cutting, raffle prizes, and general good cheer 🥳

08/17/2025

Did you catch us on the front page of the SF Chronicle this week?! Either way, catch us today at the clubhouse for the grand finale of our 90th anniversary celebration! Show and tell all day, and raffle drawing at 3pm 🙂

The San Francisco Gem & Mineral Society holds an open house to welcome new members and teach them how to turn rocks into works of art.