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Opal

· 1 min read · Materials

Opal cabochon with play of color

Opal stands out for its play of color: flashes that change with the angle. It is a beautiful, delicate gem that asks for careful handling.

Properties #

  • Composition: hydrated silica (SiO₂·nH₂O), with between 3 and 21% water.
  • Hardness: between 5.5 and 6.5 on the Mohs scale.
  • Look: the play of color comes from silica spheres that diffract light.
  • Origins: Australia produces most precious opal; also Ethiopia and Mexico.
  • Types: precious opal, fire opal, doublets and triplets (opal slices on a backing)

Uses in jewelry #

  • Rings, pendants and earrings, usually as cabochons.
  • October jewelry (birthstone).
  • Handmade and designer pieces.

Pros and cons #

Advantages #

  • Unique colors: no piece is the same.
  • Light.
  • Highly prized by collectors.

Limitations #

  • It is soft and scratches or cracks.
  • It is sensitive to heat, knocks and dehydration.
  • Some types are damaged by water (doublets and triplets).

Care and cleaning #

  • Clean only with a damp cloth and dry.
  • Do not use ultrasonic, steam, hot water or chemicals.
  • Avoid heat and prolonged sunlight.

See also #

This entry was drafted with the help of AI and is pending review by the author.