Tanzanite is only found in northern Tanzania and is used to make ornaments. It is one of the rarest gemstones on Earth, and one local geologist estimates its supply may be entirely depleted within ...

Each month has at least one gemstone; others have more. Here's what know about December's birthstones. December has three birthstones: tanzanite, turquoise and zircon. Of the three, tanzanite is ...