Definition of dioptase in English:

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Pronunciation: /dʌɪˈɒpteɪz/


[mass noun]
A rare mineral occurring as emerald green or blue-green crystals. It consists of a hydrated silicate of copper.
Example sentences
  • For digital photography, SoLux bulbs are perfect, yielding accurate rendition of difficult-to-photograph minerals such as dioptase and azurite.
  • Many of the best Tsumeb cerussite, dioptase, azurite, smithsonite, and other specimens passed through his hands en route to some faraway collection.
  • Tantara dioptase occurs well crystallized with quartz, plancheite, shattuckite, fornacite, and chrysocolla.


Early 19th century: from French, formed irregularly from Greek dioptos 'transparent'.

For editors and proofreaders

Line breaks: di|op¦tase

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