December has multiple birthstones to its name Turquoise or Blue Zircon, Blue Topaz, Lapis Lazuli, Onyx and Ruby.
Zircon has been known since antiquity. The derivation of its name is uncertain. Because of its high refractive index and strong dispersion, it has great brilliance and intense fire. There are two types of zircons, which vary greatly in their physical properties. Zircons with the highest values in optical properties and specific gravity are designated as normal or high zircon. Those with lower values are low zircon. Zircon is brittle and therefore sensitive to knocks and pressure (hardness of 6.5 to 7.5).
Zircon deposits are found in Cambodia, Burma, Thailand, and Sri Lanka. The gray-brown and red-brown are the most common and are frequently heat treated to become blue or colorless. Natural blue zircons are rare, and even rarer are green zircons.