209 - Glauconite

ID	209
Mineral	Glauconite
Location	Goslar - Nedersaksen - Germany
Fluorescence	LW-UV: close SW-UV: close
Mindat.org	View Glauconite information at mindat.org

ID	1710
Long ID	1:1:1710:3
Description	Not an IMA-approved name. This mineral has long been described in the literature and recognised by most geologists but is not easily defined. The green "glaucony" mineral commonly found in marine sediments has been defined as a mixed-layer glauconit...
Diapheny	Translucent,Opaque
About the name	Named in 1828 by Christian Keferstein from the Greek "glaukos," blue-green, in allusion to its color; but the term "glauconie" was used earlier, in 1823, by Alexandre Brongniart, as a name for the English term "green sand". Both celadonite and glauconite were lumped with "Grünerde", the approximate German equivalent of green sand, by Dana (1844). Eventually, glauconite was applied just to the sedimentary pellets, with which the species has been tied ever since, although the celadonites were essentially lumped together until the new species of the celadonite sub-group were established in 1997 by Gejing Li, Donald Ralph Peacor, Douglas S. Coombs, and Yosuke Kawachi. Rieder et al. (1998) kept glauconite as a compositional space ("series") for interlayer-deficient, Fe+/-Mg-rich dioctahedral micas, the analog of illite and related to the celadonite subgroup.
Fracture type	Micaceous
shortcode_ima	Glt
Group	Dioctahedral mica

Glauconite