Help mindat.org|Log In|Register|
Home PageMindat NewsThe Mindat ManualHistory of MindatCopyright StatusManagement TeamContact UsAdvertise on Mindat
Donate to MindatSponsor a PageSponsored PagesTop Available PagesMindat AdvertisersAdvertise on MindatThe Mindat Store
Minerals by PropertiesMinerals by ChemistryRandom MineralSearch by minIDLocalities Near MeSearch ArticlesSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
Keyword(s):
 
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
StatisticsThe ElementsMember ListBooks & MagazinesMineral Shows & EventsThe Mindat DirectoryHow to Link to MindatDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day Gallery

Greisen

This page is currently not sponsored. Click here to sponsor this page.
A medium-temperature metasomatic rock characterized by the presence of quartz and white mica, commonly with topaz, fluorite, tourmaline and locally with amazonite, orthoclase, andalusite and diaspore. Typically greisens may host Be, W, Mo, Sn and Ta mineralization. They are associated with high-level late-orogenic leucogranites and form as replacements either in the granite body and/or in a wide range of country rocks. Zoning may be present.


Classification of Greisen

Sub-divisions of Greisen

Mineralogy of Greisen

Essential minerals - these are minerals that are required within the classification of this rock:
MicaA petrological term for Mica Group.
Silica > QuartzSiO2
Non-essential minerals - these minerals are common, sometimes major components, but are not always present:
AmazoniteK(AlSi3O8)
AndalusiteAl2(SiO4)O
DiasporeAlO(OH)
Feldspar > Alkali Feldspar > OrthoclaseK(AlSi3O8)
FluoriteCaF2
Mica > MuscoviteKAl2(AlSi3O10)(OH)2
TopazAl2(SiO4)(F,OH)2
TourmalineA(D3)G6(T6O18)(BO3)3X3Z
ZinnwalditeKLiFe2+Al(AlSi3O10)(F,OH)2
Accessory minerals - these are minor components, often far less than 1% of the total mineral material:
CassiteriteSnO2
MolybdeniteMoS2
Wolframite(Fe2+)WO4 to (Mn2+)WO4

References for Greisen

Reference List:
Fettes (et al.), Metamorphic Rocks - A Classification and Glossary of Terms (2007) Cambridge University Press

Internet Links for Greisen

mindat.org URL:
https://www.mindat.org/min-48655.html
Please feel free to link to this page.
Mineral and/or Locality  
Mindat.org is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2017, except where stated. Mindat.org relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: April 28, 2017 03:36:08 Page generated: April 7, 2017 01:28:31
Go to top of page