The name jade goes back to the time of the Spanish conquest of Central and South America and derives from piedra de ijada, i.e., hip stone, as it was seen as a protection against and cure for kidney disease. In 1863, the gemstone, which had been known for 7,000 years, was proved to consist of two separate, distinct minerals, namely jadeite and nephrite. The term jade is used as a description of both. In China, nephrite was the primary form of jade used to carve mystic figures and symbols. Since 1750 jadeite, imported from Myanmar (Burma) has been used. Jadeite comes in many colors, including black.