heulandite

American  

[hyoo-luhn-dahyt] / ˈhyu lənˌdaɪt /

noun

1. a white or transparent, colorless mineral of the zeolite family, hydrous calcium aluminum silicate, CaAl 2 Si 7 O 18 ⋅6H 2 O, occurring in basic volcanic rocks in the form of crystals with a pearly luster.

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heulandite British  

/ ˈhjuːlənˌdaɪt /

noun

1. a white, grey, red, or brown zeolite mineral that consists essentially of hydrated calcium aluminium silicate in the form of elongated tabular crystals. Formula: CaAl 2 Si 7 O 18 .6H 2 O

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Etymology

Origin of heulandite

1815–25; named after Henry Heuland, 19th-century English mineral collector; -ite ¹

Example Sentences

The two minerals may, however, be readily distinguished by the fact that in heulandite the acute positive bisectrix of the optic axes emerges perpendicular to the cleavage.

From Project Gutenberg