For Immediate Release Contact: Field Museum PR Department (312) 665-7100, media@fieldmuseum.org Did You Know…? Interesting Gem Facts From A to Z Amethyst The name of this gem is derived from the Greek a methustos, meaning “not intoxicated.” Ancient Greeks fashioned jewelry and drinking vessels out of amethyst, believing that the stone could prevent drunkenness. The stone was rare until the 19th century, when huge deposits were found in Brazil. Bixbite Bixbite is thousands of times more rare than diamond. Because of its scarcity, there is not a large enough supply to make it popular. Carat The term “carat” is thought to be derived from the word kuara (seed of the African Coraltree). It also may come from the word keration (kernel of the carob bean). Both the seed and the bean were used in ancient times as counterweights on scales used to weigh gems. A carat equals two-tenths of a gram. Diamond Although diamonds were known in India 2,500 years ago, in that culture it was taboo to cut the gem because diamonds were believed to have magical properties. The taboo ended about 800 years ago. Emerald An emerald in a deep, lively green has a much higher value than one that’s pale. Flat Tops, Facets, and Fire In the 15th century, diamond cutting evolved to enhance the gem’s optical properties and the “table” emerged, an octahedral crystal with a flat top – this cut emphasized color. An engineering student at the turn of the 20th century created today’s popular “brilliant” cut of 58 facets that maximize a diamond’s fire. Gemstones Of more than 2,000 known mineral species, fewer than 40 qualify as true gemstones. Heliodor The Grainger Hall of Gems features an 8.3-carat heliodor that is cut in the shape of a hexagon. The name of the stone means “gift from the sun” in Greek. Internal Structure A raw crystal’s shape reflects the internal structure of its molecules and their atomic bonds. Jardin Fine inclusions, cracks, and fissures do not diminish the value of emerald. In fact, specialists refer to them as jardin (“garden” in French). Kimberlite It is estimated that 250 tons of volcanic rock known as kimberlite must be processed to yield a single one-carat, gem-quality diamond. Lore Opal is considered bad luck in many cultures. Matrix The original piece of rock on which a mineral grew is called matrix. It provides clues to the environment where the crystal originated. New Discovery The Field Museum recently discovered that a 56-carat sapphire in the collection could change colors. They removed the gem from a windowless room to view it in sunlight and it changed from blue to purple! Color-changing sapphires of this size are extremely rare, and this is one of the world’s largest. Oz It is speculated that The Wonderful Wizard of Oz author Frank L. Baum was inspired to create the Emerald City after seeing the dazzling White City at the 1893 World Columbian Exposition in Chicago. Who knows? Baum may also have seen the Exposition’s gem exhibition and viewed many of the pieces that are now part of The Field Museum’s collection. Pyroelectric Tourmalines become electrically charged due to change in temperature. Due to this pyroelectric charge, they attract dust and need frequent cleaning. Quality Gem quality is subjective and is based on three factors: beauty, durability, and rarity. Ruby The ancient Hindus called ruby ratnaraj or “king of precious stones.” The earliest records of ruby mining in Burma date back 3,500 years in Burma. Sri Lanka Sri Lanka is known as the “island of gems” because ruby, sapphire, alexandrite, garnet, peridot, topaz, and many other gemstones are found there in abundance. Topaz While yellow is the most common color of topaz, dark pink and red are the most valuable. Topaz comes from the Sanskrit word for fire. Unusual The Field Museum has a rare alexandrite that changes color from red in artificial light to green in sunlight. Alexandrite is an extremely rare color-changing stone and an alexandrite over 10 carats is almost unheard of. The Museum’s alexandrite, on display in the Grainger Hall of Gems, is a whopping 11.65 carats! Vertebra The Field Museum’s Hall of Gems features an opal that was formed in the fossilized vertebra of a prehistoric marine reptile that became extinct 60 million years ago. Window A very large and colorful Tiffany stained glass window has graced the Hall of Gems for years. The renovated exhibition showcases this masterpiece with state-of-the-art lighting so visitors can better experience the window’s beauty. X - 1 In the early 13th century, King Louis IX of France issued a law saying only he could wear diamonds. However within 100 years, French kings, queens, and other royals were sporting diamonds; by the 1600s, wealthy aristocrats were also wearing gems to flaunt their status. Years You think The Field Museum’s T. rex Sue is old? At 67 million years, she’s a youngster compared to diamond! Diamonds that have reached the Earth’s surface can be up to 3.6 billion years old, and ultra-deep diamonds have not yet been dated! Zircon Zircon is not to be confused with man-made cubic zirconia. As far as we know, zircon is the oldest mineral on Earth. It is also slightly radioactive. << Back to the Grainger Hall of Gems Press kit