There are two types of Jade: Jadeite and Nephrite. Jadeite is rarer and the highest quality is known as imperial Jade. Jadeite comes in many colors: red, yellow, green, lilac, black, orange, white, pink, blue and brown. Nephrite Jade is harder, more common and is often used in Chinese carvings. Nephrite Jade comes in various tones of green -- mostly with an olive green tone. The word 'jade' originates from the Spanish piedra de ijada or 'loin stone', from its reputation for curing ailments of the loins and kidneys. The earliest known jade artifacts from prehistoric sites are ornaments with bead, button, and tubular shapes. Additionally, it was used for axe heads, knives, and other weapons. When metal became available, the beauty of jade made it more valuable for ornaments and decorative objects. As early as 6000 BC Jade has been mined. Jade is the official gemstone of British Columbia, Alaska and Wyoming.