Peter Benfield mine

Mica Mine in Avery county, North Carolina

Peter Benfield mine

Principal periods worked Pre-WWII, 1943-44.
Workings Cut, adit 30
Description of muscovite Light brown, ruled, tied, small
Production Small sheet
Shape Lens
Size 1-2 T, 30 L
Strike NE
Dip SE
Relation to wallrock Concordant
Wallrock Biotite gneiss
Extent of weathering Weathered
Remarks Pl-Q-M pegmatite, fine to medium grained; accessory garnet, sericite.
Source of information USGS, CMC

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