greisen

[ grahy-zuhn ]

noun

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

greisen

/ ˈɡraɪzən /

noun

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

Word History and Origins

Origin of greisen¹

Borrowed into English from German around 1875–80

Word History and Origins

Origin of greisen¹

C19: from German, from greissen to split

Example Sentences

The analyses show the composition of Cornish granite and greisen.

From Project Gutenberg

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

From Project Gutenberg

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 Project Gutenberg

The latter is a pneumatolytic product consisting of quartz and tourmaline; it often contains white mica and thus passes by all stages into greisen.

From Project Gutenberg

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 Project Gutenberg