Tourmaline ( /ˈtʊərməlɪn/, -/iːn/ TOOR-mə-lin, -⁠leen) is a crystalline boron silicate mineral compounded with elements such as aluminium, iron, magnesium, sodium, lithium, or potassium. Tourmaline is classified as a semi-precious stone and the gemstone comes in a wide variety of colors.

According to the Madras Tamil Lexicon^[3] the name comes from the Sinhalese word “thoramalli” (තෝරමල්ලි) 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.