December's birthstone, Turquoise, is one of the most beautiful gemstones ever known to man. As the name suggests, the color is "turquoise", though the color of the gemstone varies from blue green to sky blue. The gemstone is a traditional present to commemorate 5 to 11 years of marriage.

The best turquoises are found in Iran. These best quality gemstones have that pure and radiant sky blue color, with or without its fine matrix. The more strongly the gemstone leans on the color green and the more irregular the matrix, the lower the stone's quality.

Be careful of turquoise imitations, they are quite plenty. The most common imitation of the stone is dyed magnesite and howlite. They are white in their natural states, with black veins like that of turquoises. Other less common and less convincing imitations include dyed jasper and marble. These imitations can be easily detected by gemologists through non-destructive tests, although destructive tests may deem necessary in some cases.

How do you take care of your turquoises? Always keep your stone away from bright light, heat, and make up. Do not take it with you on the beach, or anywhere with prolonged high temperatures! Clean it with a clean, soft cloth from time to time.