The easiest way to avoid buying a "fegazzi" (Italian slang for fake), is by shopping at jewelry stores that either come recommended by a reliable source, have a good history, or a seller available to answer any in-depth questions you might have about a piece. Although the majority of the stores and merchants in town are dependable, it's best to be an informed shopper to avoid discovering you bought a fake gemstone.
According to Joe Lowry, Sr., proprietor of the Turquoise Museum in Albuquerque, "only 10 percent of the turquoise being mined today is gem grade." Therefore, only a fraction of what is presented as genuine turquoise in the marketplace is a natural, untreated stone. The more shiny and perfect it looks, the more likely that it's not authentic. Real turquoise is generally flawed and is not a perfect color.
The majority of turquoise on the market still makes a great gift. Buyers are quite happy to purchase altered stones at bargain prices, as long as the merchant disclaims its quality, and the price reflects the grade of the gem. If you walk into a store that's having a sale on natural turquoise, the gems may be 100 percent genuine. If the sale price sounds too good to be true, talk to the owner and get specifics. Ask the retailer if the stone is real or genuine. Real turquoise has not been treated, only polished. A genuine stone is turquoise that may be stabilized or color enhanced. Any reputable jeweler will be glad to give you written confirmation of the value, authenticity, and the type of turquoise you're purchasing. Remember that price doesn't always dictate the authenticity of a gem.
Here are the types of turquoise commonly sold:
Natural: "High Quality Unadulterated" turquoise, cut and polished. Look for vibrant colors ranging from sky blue to green. These gems often (but not always) have a matrix-veins or blotches which vary from white to black in color. Historically, some of the finest turquoise comes from the area around Los Cerrillos and Grant County, New Mexico. Turquoise is now also mined in Iran, China, and Tibet.
Treated or stabilized: "Natural Turquoise" of low to medium quality. As the supplies of High Quality Unadulterated turquoise dwindle, the industry has developed methods for improving the durability and hardness of less desirable turquoise by saturating softer stones with a colorless stabilizing compound.
Color enhanced turquoise: Natural turquoise of poor quality that has had its hardness and color vibrancy increased artificially using a blue or green colored stabilizing compound. The industry has become so good at this processing that it is increasingly difficult to tell natural high quality turquoise from some of the better "enhanced" stones.
Block turquoise: Crushed poor quality turquoise and turquoise dust from that has been molded into blocks with colored plastics and cut and polished. This is sometimes referred to as "reconstituted" turquoise, or more commonly, "brick." Because of the resins used to bond the various materials together, this type of turquoise can often be identified by a strong "plastic" scent.
With the supplies of high quality turquoise dwindling, expect prices for these "best of breed" stones to be high, and to continue to appreciate like other precious gemstones. Don't be afraid of purchasing some of the "processed" turquoise stone products; their quality can be quite good and it puts the purchase of natural turquoise within the grasp of more people who appreciate this beautiful gemstone. As always though, caveat emptor.