Tourmaline

Tourmaline 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 the name comes from the Sinhalese
word "thoramalli" or "tōra- molli", which is
applied to a group of gemstones found in
Sri Lanka.