Name: Felsitic Gneiss
Type: rock
Class: Metamorphic
Subclass: Gneis
Particle Size: Coarse
Sample No.: gneiss3
Owner: JHU
Wavelength Range: All
Origin: Sample No. 310, The Hunt and Salisbury Collection at the U.S.Geological Survey, Denver, Co.
Collection Date: N/A
Description: This coarse to very coarse-grained sample consists of anhedra of quartz, alkali feldspar (albite, orthoclase, microcline) and brown and green biotite.  Some regions  are heavily sericitized, and sericitization has also occurred along most feldspar grain boundaries and cracks.  There are scattered opaques and some myrmeketic texture in this sample along with a trace of zircon.    Particle size was 500-1500 Micrometer. Original ASTER Spectral Library name was jhu.becknic.rock.metamorphic.gneiss.coarse.gneiss3.spectrum.txt
Modes for this rock gave 22.7% orthoclase, 22.3% both of quartz and albite, 
13.8% sericite, 7.7% microcline, 5.5% biotite and 0.7% opaques. 
