In the trade, the individual colour variants have their own names. For example, a tourmaline of an intense red is known as a 'rubellite', but only if it continues to display the same fine ruby red in artificial light as it did in daylight. If the colour changes when the light source does, the stone is called a pink or shocking pink tourmaline. In the language of the gemmologists, blue tourmalines are known as 'indigolites', yellowish-brown to dark brown ones as 'dravites' and black ones as 'schorl'. The last mentioned, mostly used for engravings and in esotericism, is said to have special powers with which people can be protected from harmful radiation.
One particularly popular variety is the green Tourmaline, known as a 'verdelite' in the trade. However, if its fine emerald-like green is caused by tiny traces of chrome, it is referred to as a 'chrome tourmaline'. The absolute highlight among the tourmalines is the 'Paraiba tourmaline', a gemstone of an intense blue to blue-green which was not discovered until 1987 in a mine in the Brazilian state of Paraiba. In good qualities, these gemstones are much sought-after treasures today. Since tourmalines from Malawi with a vivid yellow colour, known as 'canary tourmalines', came into the trade, the colour yellow, which was previously very scarce indeed, has been very well represented in the endless spectrum of colours boasted by the 'gemstone of the rainbow'.
Yet the tourmaline has even more names: stones with two colours are known as bicoloured tourmalines, and those with more than two as multicoloured tourmalines. Slices showing a cross-section of the tourmaline crystal are also very popular because they display, in a very small area, the whole of the incomparable colour variety of this gemstone. If the centre of the slice is red and the area around it green, the stone is given the nickname 'water melon'. On the other hand, if the crystal is almost colourless and black at the ends only, it is called a 'Mohrenkopf', (resembling a certain kind of cake popular in Germany).