Definition of apophyllite in English:



mass noun
  • A mineral occurring typically as white glassy prisms, usually as a secondary mineral in volcanic rocks. It is a hydrated silicate and fluoride of calcium and potassium.

    • ‘On one trip he opened a huge pocket of large analcime, natrolite, and apophyllite crystals at the Big Rock quarry and shared them with everyone.’
    • ‘True, but names such as apatite, apophyllite, chlorite, serpentine, and tantalite are very common names that appear frequently in the world of a beginning collector, so their absence from references can only lead to frustration.’
    • ‘Apophyllite forms from low temperature hydrothermal fluids.’
    • ‘The nonzeolites apophyllite, calcite, and quartz commonly occur at many localities.’
    • ‘A few specimens of apophyllite were found during the sinking of the Palmer shaft which show rosette-shaped groups and platy single crystals, some of which are half an inch across.’
    • ‘Although very beautiful, most Indian apophyllite is colorless.’
    • ‘This calcite typically overgrows quartz and crystallizes before heulandite, stilbite, and apophyllite.’
    • ‘Apophyllite is seldom seen except in comprehensive collections.’
    • ‘Apophyllite, whose name roughly means "to leaf apart" in Greek, is a mineral classic.’
    • ‘Good specimens of sperrylite with apophyllite, prehnite, thaumasite, and calcite are reported.’
    • ‘How about apatite, apophyllite, axinite, chlorite, hypersthene, scapolite, serpentine, tantalite, and wolframite?’
    • ‘The name comes from the Greek words apo (from) and fyllo (leaf) because apophyllite exfoliates (spreads or extends as if opening out leaves) when burned.’
    • ‘Most of the cavities are filled or lined with crystalline formations of various zeolites, such as stilbite, scolecite, and heulandite, plus calcite and apophyllite; these minerals typically occur in combination with each other.’
    • ‘Here, spectacularly large groups of scolecite, heulandite, apophyllite, and associated minerals occurred in cavities in flood basalt.’


Early 19th century: from apo- + Greek phullon ‘leaf’ + -ite.