Definition of tridymite in English:

tridymite

noun

  • A high-temperature form of quartz found as thin hexagonal crystals in some igneous rocks and stony meteorites.

    • ‘The abundant and ubiquitous quartz paramorphs after tridymite in the walls attest to a very shallow emplacement depth.’
    • ‘Because there is a significant difference in crystal structure among the three forms, cooling tridymite or crystoballite below 572°F results in metastable forms that retain the high temperature structure.’
    • ‘Although the optical, SEM, and XRD data are consistent with quartz, considering the incongruous crystal symmetry, it is likely that this mineral is actually a quartz pseudomorph after tridymite.’
    • ‘Quartz paramorphs after tridymite are absent from Fiachanis but present in the three Priomh-lochs samples adjacent to late minor intrusions.’

Origin

Mid 19th century: from German Tridymit, from Greek tridumos threefold from tri- three + -dumos (as in didumos twin), because of its occurrence in groups of three crystals.

Pronunciation:

tridymite

/ˈtridəˌmīt/