TOURMALINE

tourmaline

(noun) a mineral that is a complex borosilicate and hydroxide of aluminum containing iron and magnesium and calcium and lithium and sodium; it is usually black but occurs in transparent colored forms that are used as gemstones

Source: WordNet® 3.1

Etymology

Noun

tourmaline (countable and uncountable, plural tourmalines)

A complex black or dark-coloured borosilicate mineral, compounded with various chemical elements and considered a semi-precious stone.

A transparent gemstone cut from it.

Anagrams

• moluranite

Source: Wiktionary

Tour"ma*line, n. Etym: [F. tourmaline, cf. It. turmalina, tormalina, NL. turmalina, turmalinus; all fr. tournamal, a name given to this stone in Ceylon.] (Min.)

Definition: 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 .]

Note: Crystals of tourmaline when heated exhibit electric polarity (see Pyroelectric, n.). Tourmaline is also used in the form of a polariscope called tourmaline tongs.

Source: Webster’s Unabridged Dictionary 1913 Edition