Calcium Carbonate Aragonite type
CaCO3
Chemical name
Calcium Carbonate Aragonite type
Mineral name
Aragonite
Chemical formula
CaCO3
Crystal system
orthorhombic
Crystal Class
orthorhombic-dipyramidal (2/m 2/m 2/m)
Space Group
Pmcn
Unit cell
a [Å]:4.96
b [Å]:7.97
c [Å]:5.74
Molecular weight [g/mol]
100,08
Formula units
Z=4
Twinning
often on {110} cyclically and polysynthetic parallel to {100}
Mohs hardness
3.5 - 4
Density [g/cm3]
2.94
Cleavage
imperfect on {110} and {011}, indistinct on {010}
Fracture / Tenacity
brittle, conchoidal
Color
white, red, yellow, orange, green, purple, gray, blue, brown
Streak
white
Transparency
translucent to transparent
Optical character
biaxial (-)
Refractive Index
nα=1.529-1.530; nβ=1.680-1.682; nΥ=1.685-1.686
Birefringence δ
0.156
Pleochroism δ
none