The Oregon Museum of Science and Technology (OMSI) in Portland has an interesting display of minerals.
Museums 101: Thunder Eggs (Photo Diary)
Museums 101: Gems and Minerals as Art (Photo Diary)
Museums 101: California Gems and Minerals (Photo Diary)
Museums 101: The Hixon Gem Vault (Photo Diary)
Museums 101: South American Gems and Minerals (Photo Diary)
Museums 101: Gold (Photo Diary)
Museums 101: The Gem and Mineral Hall (Photo Diary)