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- Mica deposits of the Blue Ridge in North Carolina
Mica Mine in Avery county, North Carolina, this site also known as Iva Johnson, Callahan
Franklin (Iva Johnson, Callahan) mine
Principal periods worked |
WWI, WWII, 1954 (?). |
Workings |
Cut 50, adit, stope 75 |
Description of muscovite |
Greenish brown, bent, stained, locky |
Production |
Small sheet |
Shape |
Tabular |
Size |
30 T |
Strike |
NW |
Dip |
SW |
Relation to wallrock |
Concordant |
Wallrock |
Interlayered biotite and hornblende schist |
Extent of weathering |
Unweathered |
Remarks |
P-Pl-Q-M pegmatite, fine to medium grained; accessory garnet, allanite, apatite, sericite. |
Source of information |
USGS, CMC |
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 |