Definition of cristobalite in US English:



  • A form of silica which is the main component of opal and also occurs as small octahedral crystals.

    • ‘Look up cristobalite in the textbook and describe a likely environment for the formation of this sample.’
    • ‘The conversion of feldspar to cristobalite involves the removal of water.’
    • ‘Analyses of some samples of the dense grey rimstone sinter showed weak reflections, indicating the possible presence of cristobalite.’
    • ‘Atoms of aluminum and sodium in the structure may help the stability of cristobalite as well.’
    • ‘All quartz is not the same - there are differences that do affect cristobalite generation - the ground quartz does produce more cristobalite.’


Late 19th century: named after Cerro San Cristóbal in Mexico, where it was discovered, + -ite.