The world's largest cut topaz, called the American Topaz, resides at the Smithsonian Institution in Washington, DC. A 172-faceted topaz weighing 22,892.50 carats (5785 kg), it's the largest cut yellow topaz in the world, and one of the largest faceted gems of any kind in the world. Originating from Minais Gerais, Brazil, it was cut over a period of two years. It was purchased by the Rockhound Hobbyists of America and presented to the Smithsonian Institution in 1988.

As stunning as this cut topaz is, another display at the Smithsonian is equally dazzling and awe-inspiring. That's a sherry-colored topaz ?spray? from the Thomas Range in Utah. This color of topaz can be found in Mexico and Utah, but when it's exposed to sunlight, will become clear.

Other spectacular displays of natural crystals include a cluster of Stibnite, an ore of antimony, which has a bright metallic luster. This spectacular group of crystals is from Iyo, Japan and look like something from Superman's home!

Another huge mineral in the exhibit is the Smithsonite, named for James Smithson, who bequeathed the funds to establish the Smithsonian Institution. He first discovered this greenish zinc carbonate mineral from the Kelly Mine in New Mexico.

Some of the other don't miss items in the Smithsonian's Gem Collection are the Smithsonian Canary Diamond, a huge canary and diamond ring. The 98.6-carat Bismarck Sapphire is also part of the collection and is one of the world's largest sapphires. It originally came from Sri Lanka. It's also fascinating to see some of these gems in their raw uncut state, such as the large corundrum crystal which is the mineral that sapphires are made of, and a very large beryl crystal, from which the emerald and aquamarine family of stones is derived.