CaCO3 (calcite/aragonite)Trigonal/Orthorhombic
Coral
CaCO3 (calcite/aragonite)
OrganicChemical FormulaCaCO3 (calcite/aragonite)
Crystal SystemTrigonal/Orthorhombic
Mohs Hardness3.5
Specific Gravity2.7
ColorRed, pink, orange, white
LusterVitreous to dull
StreakWhite
CleavageNone
FractureUneven
Occurrence
Formed by marine organisms. Red coral used in jewelry. Protected in many areas.