The gemstone of the week this week is Tiger's Eye. There are several variations on the name, among them Tiger Eye and Tigereye. All the names refer to the silky, golden brown gemstone of the quartz family. It is a brown quartz silcon dioxide with yellow and brown parallel fibers. Iron oxide gives the stone it's yellow gold color. The glitter on the surface of the stone is known as chatoyancy (sha-toy-ancee).
Tiger's Eye is a vitreous stone-hard, unbendable and glasslike. On the Moh scale it is a 7. This makes it suitable for all types of jewelry, although care should be taken against exposing it to sudden temperature changes, as that could cause the stone to crack.
Tiger's Eye is usually cut as cabochons as this best shows off the chatoyancy and color. Heat treatment is the usual enhancement for this gemstone. Red Tiger's Eye is heat treated. The heat oxidizes the iron and turns it red. Years ago, I had some Tiger's Eye stones. My mom and I put them on a cookie sheet, in a 325 degree oven for 12 hours and they turned a lovely red. To prevent cracking,we did not preheat the oven, but put the stones in the oven, then turned it on, allowing the stones to gradually warm. Every couple of hours, we would turn the stones with tongs. We also left them in the oven to gradually cool down after we turned the oven off.
Tiger Eye is mainly found in South Africa, but is also found in Austrailia, Myanmar, Namibia and California.
Tiger Eye is said to help lower blood pressure, help with asthma and heart disease. It is also believed to pull someone into a more flexible and positive attitude and give the wearer courage and confidence. Roman soldiers often wore carved Tiger Eye into battle.
In these photos, you can see the different banding and how each stone varies.