The family of tourmalines is very numerous and unites a number of minerals with similar characteristics and a diverse range of colors: from black, blue and red to green and colorless. Some varieties of tourmaline are polychrome, i.e. painted in several colors at once. The most interesting and beautiful varieties of tourmaline are considered to be black tourmaline, indigolite, rubellite and verdelite (green tourmaline).
Black tourmaline contains sodium, iron and aluminum. This mineral has a high hardness and is capable of changing color depending on the angle of incidence of light. For a long time, it was used to make funeral jewelry. It gained special popularity in England in the Victorian epoch.