Definition

1. Noun:
   • A complex crystalline mineral: Tourmaline is a mineral belonging to a complex group of borosilicate compounds. It often contains various elements such as aluminum, iron, magnesium, calcium, lithium, and sodium, along with hydroxide ions.
   • A gemstone: Transparent and vividly colored varieties of tourmaline are highly valued and cut for use as gemstones in jewelry.

Examples of Usage

• Noun:
  • The geologist identified the black crystal as tourmaline.
  • She wore a beautiful ring set with a pink tourmaline.
  • Tourmaline is notable for its ability to become electrically charged when heated.

Advanced Usage

• Descriptive Use: The term is often modified by color to specify a variety.
  • Watermelon tourmaline exhibits bands of pink, green, and white.
  • The Paraíba tourmaline, known for its vivid blue-green color, is exceptionally rare.

Variants and Related Words

• Tourmalinic (adj): Relating to or containing tourmaline.
  • The rock had a tourmalinic composition.

Synonyms

• Semi-precious gemstone (when referring to its use in jewelry; note: this is a category, not a direct synonym for the mineral itself).

Different Meanings

• The word tourmaline refers specifically to the mineralogical group and its gem varieties. It does not have other common metaphorical or idiomatic meanings.

Notes

• Tourmaline is prized in gemology for its wide range of colors, which can sometimes occur in a single crystal. It is also known for its pyroelectric and piezoelectric properties (generating an electrical charge under heat or pressure).

Noun

1. 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