Tourmaline ( /ˈtʊərməlɪn/, –/iːn/ TOOR-mə-lin, -leen) is a crystalline boron silicate mineral compounded with elements such as aluminum, iron, magnesium, sodium, lithium, or potassium. Tourmaline is classified as a semi-precious stone and the gemstone comes in a wide variety of colors.
Brightly colored Sri Lankan gem tourmalines were brought to Europe in great quantities by the Dutch East India Company to satisfy a demand for curiosities and gems. At the time, it was not realized that school and tourmaline were the same minerals, as it was only about 1703 that it was discovered that some colored gems were not zircons. Tourmaline was sometimes called the “Ceylonese [Sri Lankan] Magnet” because it could attract and then repel hot ashes due to its pyroelectric properties.
Tourmalines were used by chemists in the 19th century to polarize light by shining rays onto a cut and polished surface of the gem.
According to the Madras Tamil Lexicon, the name comes from the Sinhalese word “thoramalli” or “tōra- molli”, which is applied to a group of gemstones found in Sri Lanka. According to the same source, the Tamil “tuvara-malli” (துவரைமல்லி) and “toramalli” are also derived from the Sinhalese root word. This etymology is also given in other standard dictionaries including the Oxford English Dictionary.