Powdermill Creek mine

Mica Mine in Avery county, North Carolina

Powdermill Creek mine

Workings Cut 80, 2 adits
Description of muscovite Brown, minor "A" structure, commonly cracked, tied, stained, bent.
Production Small sheet
Shape Lens
Size 3 T
Strike NW
Dip SW
Wallrock Interlayered hornblende and biotite gneiss
Extent of weathering Partly weathered.
Remarks Pl-Q-M pegmatite, medium to coarse grained; accessory sericite, tourmaline.
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