World Library  
Flag as Inappropriate
Email this Article


Article Id: WHEBN0020496291
Reproduction Date:

Title: Greenalite  
Author: World Heritage Encyclopedia
Language: English
Subject: Phyllosilicates, Minnesotaite, Iron ore
Collection: Phyllosilicates
Publisher: World Heritage Encyclopedia


Category Phyllosilicates
Kaolinite-serpentine group
(repeating unit)
Strunz classification 09.ED.15
Unit cell a = 5.54 Å, b = 9.55 Å, c = 7.44 Å, β = 104.2°; Z=2
Color Green, light yellow-green
Crystal habit Rare minute crystals, rounded grains common; as porphyroblasts, oolites
Crystal system Monoclinic
Cleavage None
Mohs scale hardness 2.5
Luster Dull, earthy
Streak Greenish-gray
Diaphaneity Translucent to subopaque
Specific gravity 2.85 - 3.15
Optical properties Biaxial (+)
Refractive index nα = 1.650 - 1.675 nβ = 1.674 nγ = 1.674
Birefringence δ = 0.024
Pleochroism X = pale yellow, Y and Z = green
Other characteristics Magnetic
References [1][2][3]

Greenalite is a mineral in the kaolinite-serpentine group with the chemical composition (Fe2+,Fe3+)2-3Si2O5OH4.[1][4] It is a member of the serpentine group.[2]


Greenalite was first described in 1903 for an occurrence in the Mesabi Range near Biwabik, St. Louis County, Minnesota and named for its green color.[2]

Greenalite occurs as a primary phase in banded iron formations. Rocks which contain greenalite are usually bright green, pale green or pale brown. Greenalite occurs with quartz, stilpnomelane, siderite, chamosite, pyrite and minnesotaite. It is commonly oolitic.[1]


  1. ^ a b c Handbook of Mineralogy
  2. ^ a b c Greenalite on
  3. ^ Greenalite on Webmineral
  4. ^ Sleep N.H., Bird D.K. (2007): Niches of the pre-photosynthetic biosphere and geologic preservation of Earth’s earliest ecology. Geobiology 5, 101-117

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.