trigonal
Calcite (Nailhead Spar)
CaCO3
Quick Facts
Hardness
3
Specific Gravity
2.71
Refractive Index
1.486-1.658
Crystal Structure
trigonal[-3m]:{0001}@1.0 + {10-11}@0.4 trigonal
-3m
{0001} {10-11}
Physical Properties
Crystal Systemtrigonal
Hardness (Mohs)3
Specific Gravity2.71
CleavagePerfect rhombohedral {10-11}
FractureConchoidal
LustreVitreous to pearly on pinacoid
Optical Properties
Refractive Index1.486-1.658
Birefringence0.172
PleochroismNone
Dispersion0.017
Interactive Preview
Open this crystal in the CDL Playground to rotate, export, and explore in 3D.
Open in Playground trigonal[-3m]:{0001}@1.0 + {10-11}@0.4 Related Minerals
Other minerals in the trigonal system