About Us

The Mineral & Gem Society of Castro Valley was established in 1948 as a non-profit and educational organization.

Our purpose is to:

  • Increase knowledge and understanding of the earth sciences pertaining to minerals, gems, fossils, rocks, geology, and related subjects
  • Encourage the practical art of cutting, grinding, and polishing of these materials and their use in the design and creation of jewelry or art
  • Encourage members' participation in displaying and exhibiting their work for public educational purposes
  • Encourage field trips to study rocks, minerals, fossils, and the geology in natural geological settings
  • Encourage and assist junior members in furthering their interest in minerals, gems, and related subjects

All sales go towards keeping our shop doors open and funding our non-profit operations.