December - Blue Zircon / Turquoise
Hindu poets tell of the Kalpa Tree, the ultimate gift to the gods, which was a glowing tree covered with gemstone fruit with leaves of zircon. Zircon has long had a supporting role to more well-known gemstones, often stepping in as an understudy when they were unavailable.
In the middle ages, zircon was said to aid sleep, bring prosperity, and promote honor and wisdom in its owner. The name probably comes from the Persian word zargun which means "gold-colored," although zircon comes in a wide range of different colors.
Natural zircon today suffers for the similarity of its name to cubic zirconia, the laboratory-grown diamond imitation. Some don't realize that there is a beautiful natural gemstone called zircon.
Zircon occurs in a wide range of colors but for many years, the most popular was the colorless variety which looks more like diamond than any other natural stone due to its brilliance and dispersion.
Today the most popular color is blue zircon. Most blue zircon, which is considered an alternate birthstone for December, is a pastel blue, but some exceptional gems have a bright blue color. Zircon is also available in green, dark red, yellow, brown, and orange.
Zircon is mined in Cambodia, Sri Lanka, Thailand, Myanmar, Australia, and other countries.
Zircon is one of the heaviest gemstones, which means that it will look smaller than other varieties of the same weight. Zircon jewelry should be stored carefully because although zircon is relatively hard, it can abrade and facets can chip. Dealers often wrap zircons in individual twists of paper so that they will not knock against each other in a parcel.
The wide variety of colors of zircon, its rarity, and its relatively low cost make it a popular collector's stone. Collectors enjoy the search for all possible colors and variations.
Mohs hardness: 7.0 to 7.5
History and Folklore:
Old European tradition associates turquoise with horses. Turquoise supposedly protected horses from all manner of ills, including drinking overly cold water when overheated. The bearer of turquoise should be able to resist evil and maintain virtue. Tibetans believe that turquoise brings good fortune and health, and wards off the evil eye. Turquoise was more valuable than gold to the Aztecs of Mexico - a notion that was passed on to the conquering Spaniards. The name "turquoise" is fairly recent. Pliny referred to it instead as callais, with comes form the Greek kalos lithos meaning "beautiful stone." One who sees the reflection of the new moon on turquoise will have good luck, according to Persian legend. The Hindus thought a similar combination would bring great wealth. And the Navajos thought that a prayer spoken while throwing turquoise into the river would bring rain.
Turquoise was thought to be amorphous until the first crystalline specimens were found in 1911. Spiderweb turquoise is veined with black matrix in a pattern that looks like crocheted lace. Though often associated with Native Americans, turquoise has been known globally since the Mesopotamians used it by 5000 B.C.
Turquoise may well have been the first gemstone mined and the first imitated.The color of blue turquoise can change under heat (about 500oF) to greener hues.There are several minerals that make the dark veins often found in turquoise. These include limonite, sandstones, jaspers, and psilomelane. Veins of other colors occur as well with minerals such as malachite and chrysocolla.
The name turquoise means Turkish, refering to the fact that Europe's early turquoise got to Europe via Turkey. Avoid contacting turquoise with body oils (or any oils, for that matter). The stone is porous and will absorb oils causing the color to yellow over time. The finest color is an intense deep-blue azure, rarely seen. The intensity and evenness of color are important valuation factors. So too is the quality of the polish. "Robin's egg blue" is another highly valued color.
Turquoise is found in Iran (Persian turquoise is of the finest; it is Iran's national gemstone), Afghanistan, Australia, China, Israel, Tanzania, Russia, Chile, Mexico, Brazil, and the U.S. Folks who know their turquoise can tell you what mine a particular specimen came from based on its color and matrix pattern. The differences can be very subtle, however, and the breadth of variation is enormous.
Turquoise is often dyed to improve the color. (It is very porous.) It may also be stabilized by a polymer acting as a binder for the otherwise softer and more porous natural material. This can be overdone, however, with some materials called "turquoise" containing less than 10% natural turquoise.
Dyed chalcedony, dyed howlite, glasses, ceramics, and plastics. Pieces of turquoise are pulverized and reconstituted to look like natural turquoise. There are some other minerals that can be confused with turquoise: amazonite, chrysocolla, lazulite, hemamorphite, odontolite, serpentine, smithsonite, faustite, prosopite, and variscite. Even the early Egyptians imitated turquoise with a glazed quartz paste (faience) due to the inferior quality of the available turquoise.
This is marketed under such names as hamburger turquoise, neolite, and neo-turquoise
Mohs hardness: 5.0 to 6.0