Gemstones are used to create jewelry and decorate objects. The chemistry of gemstones also reveals clues about the formation of our planet. On this recent episode of PBS's NOVA, available for free streaming on this website, visitors can learn more about the science behind gemstones. The documentary, part of a three-part series on "treasures of the earth," features interviews with a diverse group of experts, including geologists, chemists, jewelers, and mining professionals. In addition, the documentary features gorgeous footage of a number of gemstones. The film is accompanied by a number of related links, including an extensive glossary of gems and articles about the history and science behind diamonds and pearls. Fans of this documentary can also check out the remaining videos in the Treasures of the Earth series, includes documentaries on metals and natural sources of power.