There are two types of jade; jadeite and nephrite.  Jadeite is a precious gem and in its pure form it is white but also is green, lilac/lavender, pink, brown, red, blue, black, orange, and yellow.  Jadeite is the most valuable type of Jade.  Imperial jade is a rich emerald or apple green.  Nephrite jade is stronger than steel as it was once used for tools like arrows and axe heads.