One of the galleries in the Los Angeles County Museum of Natural History is dedicated to gems and minerals. Within this gallery is the Hixon Gem Vault which contains one of the finest collections of gemstones in North America. Photographs of some of the displays are shown below.
Museums 101
Museums 101 provides photo tours of different museums. More gems and minerals:
Museums 101: Gems and Minerals as Art (Photo Diary)
Museums 101: California Gems and Minerals (Photo Diary)