Cambodian blue zircon. Stone cut, photographed, and sold by Dan Starr at Dan Starr Gems
On this last day of the last month of the year I chose a stone named with the last letter of the alphabet that is concurrently the oldest known mineral on earth. Often a sparkling icy blue or white when seen in stores, zircon is one of the traditional December birthstones and was an unexpected treat to research.
The base chemical formula is ZrSiO4 but there are trace amounts of radioactive elements like uranium and thorium that degrade over time. Zircon is actually a very common mineral worldwide but it is rarely found in large crystals. It has a higher refractive index than tanzanite, spinel, and corundum (rubies and sapphires), with a brilliant fire in the gem-quality stones.
Rough zircon from Ethiopia, for sale at minedirect.com
Zircon has had many names over the centuries, but its current moniker is believed to come from the Persian words for “gold” and “like,” referring to one of its common colors. It can take on any shade but the conditions needed to form green stones are exceptionally rare. The colors can be affected by natural or manmade heat and radiation, which is often used to create the vibrant blues. The oldest identified zircon is from Australia and was dated at 4.4 billion years old (Earth is thought to be 4.57 billion years old).
Sri Lanka, Burma, and Cambodia are common sources of zircon, with Tanzanian stones being newcomers to the market. Zircon is pretty affordable and durable at 6.5-7.5 Mohs, but it should be worn and cleaned with some care. Though often (and unfortunately) confused with cubic zirconia and a historical stand-in for diamond and topaz, zircon is a beautiful stone on its own and has adorned the heads of many kings and queens.
While the different colors are given their own metaphysical attributes, zircon is thought of as a peace-bringing stone. Hindu writings describe a mystical, wish-fulfilling Kalpa tree made of dazzling gems, and its mature leaves are green zircons. The stone is mentioned in the Bible, and reportedly there is a Jewish tale where Zircon is the name of an angel that watched over Adam and Eve in Eden.
Heated Cambodian rough zircon, sold through Gem Rock auctions
Happy New Year everyone!