-
nouna mineral that is a complex borosilicate and hydroxide of aluminum containing iron and magnesium and calcium and lithium and sodium; it is usually black but occurs in transparent colored forms that are used as gemstonestype of:
Definition that contains tourmaline
- pyroelectricity generation of an electric charge on certain crystals (such as tourmaline) as a result of a change in temperature
- schorl black tourmaline