orthorhombic Carbonates
Aragonite
CaCO3
Quick Facts
Hardness
3.5
Specific Gravity
2.93
Refractive Index
1.53
Optical Character
Biaxial -
Crystal Structure
#! Species: Aragonite
#! System: Orthorhombic (mmm)
#! Habit: Prismatic with multiple dome faces
orthorhombic[mmm]:{110}@1.0 + {010}@0.7 + {011}@0.6 + {021}@0.4
orthorhombic
mmm
{110} {010} {011} {021}
Physical Properties
Crystal Systemorthorhombic
Hardness (Mohs)3.5
Specific Gravity2.93
CleavageGood {010}, poor {110} and {011}
FractureSubconchoidal to splintery
LustreVitreous to resinous
Optical Properties
Refractive Index1.53
Birefringence0.155
Optical CharacterBiaxial -
Dispersion0.014
PleochroismNone
Colours
ColorlessWhiteBlueYellowGreenBrownOrange (flos ferri variety)
Localities
Spain (Aragon - type locality)Morocco (spectacular twins)Namibia (blue)MexicoUSA (various)Worldwide in caves and hot springs
Crystal Forms
prismpinacoidpseudohexagonal twins
Notes
Extremely high birefringence; dissolves in dilute HCl with effervescence; forms nacre in shells
Interactive Preview
Open this crystal in the CDL Playground to rotate, export, and explore in 3D.
Open in Playground #! Species: Aragonite
#! System: Orthorhombic (mmm)
#! Habit: Prismatic with multiple dome faces
orthorhombic[mmm]:{110}@1.0 + {010}@0.7 + {011}@0.6 + {021}@0.4
Related Minerals
Other minerals in the orthorhombic system
