1. Mineral Resources
  2. Online Spatial Data
  3. Mica deposits of the Blue Ridge in North Carolina

Twiggs mine

Map
XML
JSON
KML
Mica Mine in Mitchell county, North Carolina

Twiggs mine

Principal periods worked WWII, 1956-58
Workings 4 Adits, shaft 100, stopes, drift 93.
Description of muscovite Greenish brown, hard, bent, cracked, stained.
Production Moderate sheet
Shape Tabular, pinch and swell.
Size 0.1-3 T, 200 L, 150 D.
Strike NE
Dip SE
Plunge NE
Relation to wallrock Concordant
Wallrock Interlayered biotite and hornblende gneiss
Extent of weathering Unweathered
Remarks Pl-Q-M pegmatite, fine to medium grained; accessory garnet, pyrite, chlorite, epidote, biotite.
Source of information USGS, DMEA

Geographic context

(click for info)
Geologic map unit -82.073107188, 36.043061441
Nearby scientific data Find additional scientific data near this location

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