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Webster 1913 Edition


Tourmaline

Tour′ma-line

,
Noun.
[F.
tourmaline
, cf. It.
turmalina
,
tormalina
, NL.
turmalina
,
turmalinus
; all fr.
tournamal
, a name given to this stone in Ceylon.]
(Min.)
A mineral occurring usually in three-sided or six-sided prisms terminated by rhombohedral or scalenohedral planes. Black tourmaline (schorl) is the most common variety, but there are also other varieties, as the blue (indicolite), red (rubellite), also green, brown, and white. The red and green varieties when transparent are valued as jewels.
[Written also
turmaline
.]
☞ Crystals of tourmaline when heated exhibit electric polarity (see
Pyroelectric
,
Noun.
). Tourmaline is also used in the form of a polariscope called tourmaline tongs.

Definition 2024


tourmaline

tourmaline

English

Bi-colored tourmaline crystal, 2 cm long.

Noun

tourmaline (plural tourmalines)

  1. A complex black or dark coloured borosilicate mineral, compounded with various chemical elements and considered a semi-precious stone.
    • 2012 March 1, Lee A. Groat, “Gemstones”, in American Scientist, volume 100, number 2, page 128:
      Although there are dozens of different types of gems, among the best known and most important are []. (Common gem materials not addressed in this article include amber, amethyst, chalcedony, garnet, lazurite, malachite, opals, peridot, rhodonite, spinel, tourmaline, turquoise and zircon.)
  2. A transparent gemstone cut from it.

Derived terms

Related terms

Translations


French

Noun

tourmaline f (plural tourmalines)

  1. tourmaline