The three birthstones of December are zircon, tanzanite and turquoise. All of these birthstones come in a variety of shades of blue. Tanzanite is found exclusively in Tanzania and has often been purchased as a sapphire substitute since it is less expensive.
Major sources of zircon include Thailand, Cambodia and Vietnam. According to folk wisdom, zircon relieves pain, protects travelers from injury and disease, whets the appetite, and prevents nightmares. Zircon also comes in yellow, orange, red, brown, green and colorless in addition to blue. Turquoise ranges in transparency from translucent to opaque and is a favorite gemstone in the American Southwest.