"The earliest record of turquoise being used in jewelry or in ornaments is from Egypt. There turquoise has been found in royal burials over 6000 years old. About 4000 years ago, miners in Persia produced a blue variety of turquoise with a "sky blue" or "robin's egg blue" color. This material was very popular and traded through Asia and into Europe. This is the source of the term "Persian Blue" color."