Jacob W. Henry mine

Mica Mine in Macon county, North Carolina, this site also known as Jake Henry; Rocky Face

Jacob W. Henry (Jake Henry; Rocky Face) mine

Principal periods worked Pre-1910, 1942
Workings Cut 25 long, 20 deep
Description of muscovite Brown, bent, tangle sheet, biotite intergrowths.
Shape Irregular
Size 3-15 T
Strike NE
Dip SE
Relation to wallrock Partly concordant
Wallrock Biotite gneiss
Remarks F-Q-M-B wall zone; Q core, discontinous.
Source of information Sterrett (1923, p. 226), 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