White Rock (north) mine

Mica Mine in Avery county, North Carolina

White Rock (north) mine

Principal periods worked Pre-WWII
Workings Adit
Description of muscovite Ruby, clear
Production Small sheet
Shape Lenses
Size 1-4 T, 6-16 L
Strike NE
Dip SE
Relation to wallrock Concordant
Wallrock Interlayered hornblende and biotite gneiss
Extent of weathering Unweathered
Remarks Pl-Q-M-P pegmatite, fine to medium grained; accessory garnet.
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