The word tourmaline derives from the Sinhalese language of Sri Lanka, where turamali (තුරමලි) described certain colorful gemstones found on the island. This Sinhalese origin places tourmaline among a small but notable group of English words borrowed from the languages of Sri Lanka, reflecting the island's historical importance as a source of precious gemstones.
Sri Lanka (known to Europeans as Ceylon until 1972) has been famous for its gemstones since antiquity. The island's geological richness produces sapphires, rubies, garnets, and many other precious and semiprecious stones, earning it the Arabic title Serendib — the Island of Gems — which also gave English the word serendipity. Dutch colonial traders, who controlled much of Sri Lanka's gem trade in the seventeenth and eighteenth centuries, adopted the Sinhalese word turamali for the colorful boron silicate minerals that were among the island's many mineralogical offerings.
The word traveled from Dutch trading networks into French scientific vocabulary in the mid-eighteenth century, when mineralogists were systematically classifying the mineral kingdom. French tourmaline was adopted into English around 1759, during a period of intense scientific interest in mineralogy and crystallography.
Tourmaline's extraordinary color range makes the Sinhalese name — meaning mixed-color stones — particularly apt. The mineral occurs in virtually every color of the spectrum: black (schorl), blue (indicolite), green (verdelite), pink to red (rubellite), and colorless (achroite). Some crystals display multiple colors in a single specimen — watermelon tourmaline shows green exterior and pink interior, while bi-colored crystals display distinct color zones along their length.
Beyond its beauty, tourmaline possesses remarkable physical properties that connect it to the history of science. When heated, tourmaline crystals develop an electrical charge on their surfaces — a property called pyroelectricity. When compressed, they generate a different kind of electrical charge — piezoelectricity. Benjamin Franklin studied tourmaline's electrical properties in the 1740s, and the mineral played a role in the early investigation of electricity and crystallography.
These electrical properties gave tourmaline practical applications beyond jewelry. Tourmaline crystals were used in pressure-sensing devices, and the mineral's optical properties — particularly its ability to polarize light — made it useful in early scientific instruments. Modern applications include use in pollution-monitoring equipment and certain electronic components.
The gem trade in tourmaline has expanded dramatically since the discovery of major deposits in Brazil, Nigeria, Mozambique, and Afghanistan. The Paraíba tourmaline, a vivid neon blue-green variety discovered in Brazil in 1989, became one of the most valuable gemstones in the world, commanding prices that rival fine diamonds. This commercial success has ensured that the Sinhalese word turamali, adopted by Dutch traders centuries ago, remains a vital term in the global gem trade.