Barrett mine

Mica Mine in Avery county, North Carolina

Barrett mine

Principal periods worked Pre-WWII
Workings Cut 225, 2 stopes
Description of muscovite Green, wedge "A" structure, concentrated in core; Brown, biotite intergrowths, concentrated in wall zone.
Production Moderate sheet, scrap, large feldspar.
Shape Tabular
Size 50 T, 225 L
Strike NE
Dip SE
Relation to wallrock Concordant
Wallrock Biotite gneiss
Remarks Pl-P-Q-M wall zone, accessory biotite, vermiculite, garnet; P-Pl-Q-M core, coarse grained.
Source of information USGS

Geographic context


Principal periods worked
WWI World War I
WWII World War II
int intermittent
Small < 500 lb
Moderate 500-10,000 lb
Large > 10,000 lb
Size of pegmatite
D depth
L length
T thickness
avg average
Internal structure
B biotite
F feldspar
M muscovite
P perthite
Pl plagioclase
Q quartz
Source information
CMC Colonial Mica Corporation
DMEA Defense Minerals Exploration Administration
OME Office of Minerals Exploration
USGS U.S. Geological Survey
OF USGS open-file reports and maps