greisen

American  

[grahy-zuhn] / ˈgraɪ zən /

noun

1. a hydrothermally altered rock of granitic texture composed chiefly of quartz and mica, common in the tin mines of Europe.

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greisen British  

/ ˈɡraɪzən /

noun

1. a light-coloured metamorphic rock consisting mainly of quartz, white mica, and topaz formed by the pneumatolysis of granite

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Etymology

Origin of greisen

Borrowed into English from German around 1875–80

Example Sentences

They make it clear that there has been an introduction of fluorine and boron and a diminution in the alkalies during the transformation of the granitic rock into the greisen.

From Encyclopaedia Britannica, 11th Edition, Volume 12, Slice 5 "Greek Law" to "Ground-Squirrel" by Various

The wall rocks are usually strongly altered and in part are replaced by some of the above minerals, forming coarse-grained rocks which are called "greisen."

From The Economic Aspect of Geology by Leith, C. K. (Charles Kenneth)

The analyses show the composition of Cornish granite and greisen.

From Encyclopaedia Britannica, 11th Edition, Volume 12, Slice 5 "Greek Law" to "Ground-Squirrel" by Various

Cassiterite usually occurs as veins or impregnations in granitic rocks, and is especially associated with the quartz-mica rock called greisen.

From Encyclopaedia Britannica, 11th Edition, Volume 5, Slice 4 "Carnegie Andrew" to "Casus Belli" by Various

The transition between the two rocks is perfectly gradual, a fact which shows that the greisen has been produced by alteration of the granite.

From Encyclopaedia Britannica, 11th Edition, Volume 12, Slice 5 "Greek Law" to "Ground-Squirrel" by Various