Houston Rock mine

Mica Mine in Avery county, North Carolina

Houston Rock mine

Principal periods worked 1913-14, 1923-24, 1942.
Workings 4 cuts, 2 short stopes, adit 45.
Description of muscovite Brown, moderately stained, biotite intergrowths, concentrated in wall zone; green "A" structure, in core.
Production Moderate sheet
Shape Lenses
Size 3-10 T
Strike NE
Dip SE
Relation to wallrock Concordant
Wallrock Mica gneiss
Remarks Pl-P-Q-M wall zones, medium to coarse grained; accessory biotite, garnet, pyrite; Q-M core, discontinuous.
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