December's Birthstone, turquoise was among the first gemstones ever mined. Turquoise has long been known as the "Stone of Luck." Stunning sky blues to stimulating sea greens have made turquoise one of the most popular color trends in jewelry history. Copper gives turquoise its range of blue hues while iron is responsible for its green colors. Treasured since the days of ancient Egypt, and the thousands of years since, turquoise jewelry is said to bring good fortune and happiness to those who wear it.