The Hillman Hall of Minerals and Gems
Gemstone collection of about 2,300 pieces. Recent acquisitions include an outstanding suite of minerals from the former Soviet Union and an historically important suite of Pennsylvania minerals formerly owned by the Academy of Natural Sciences in Philadelphia. http://www.carnegiemnh.org/minerals/
Multicolour Gems Co., Ltd.
Specializing in African colored gemstones including alexandrite, Madagascar sapphire and tanzanite. Also includes general information about gemstones and gemological articles http://www.multicolour.com/
