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- Mica deposits of the Blue Ridge in North Carolina
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. |
Abbreviations
Principal periods worked
WWI |
World War I |
WWII |
World War II |
int |
intermittent |
Production
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 |