The main sources are Guatemala, Burma and SW China. This rare form of jade polishes up to a mirror finish. There is some confusion about chloromelanite being a third type of jade: both jadeite and nephrite. There is no question that it is jadeite and should be referred to as such.
Mayans made tools from chloromelanite jadeite because it was not as appealing as the green, blue and lavender more suitable for jewelry. If the Maya had better polishing techniques, there would be more black jadeite jewelry.
- Roger Keverne, Jade