apophyllite

American  

[uh-pof-uh-lahyt, ap-uh-fil-ahyt] / əˈpɒf əˌlaɪt, ˌæp əˈfɪl aɪt /

noun

1. a hydrous potassium and calcium silicate mineral occurring in white crystals.

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apophyllite British  

/ əˈpɒfɪˌlaɪt, ˌæpəˈfɪlaɪt /

noun

1. a white, colourless, pink, or green mineral consisting of a hydrated silicate of calcium, potassium, and fluorine in tetragonal crystalline form. It occurs in cracks in volcanic rocks. Formula: KCa 4 (Si 4 O 10 ) 2 (OH 1 F).8H 2 O

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Etymology

Origin of apophyllite

First recorded in 1800–10; apo- + -phyll + -ite ¹

Example Sentences

Also some tetragonal and hexagonal crystals, e.g. apophyllite, vesuvianite, beryl, &c., which should normally be optically uniaxial, sometimes consist of several biaxial portions arranged in sectors or in a quite irregular manner.

From Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 7 "Crocoite" to "Cuba" by Various

Examples of substances which crystallize in this class are cassiterite, rutile, anatase, zircon, thorite, vesuvianite, apophyllite, phosgenite, also boron, tin, mercuric iodide.

From Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 7 "Crocoite" to "Cuba" by Various

When heated before the blowpipe, the mineral exfoliates, owing to loss of water, and on this account was named apophyllite by R.J.

From Encyclopaedia Britannica, 11th Edition, Volume 2, Slice 3 "Apollodorus" to "Aral" by Various