ZrSiO4Tetragonal
Zircon
ZrSiO4
SilicatesChemical FormulaZrSiO4
Crystal SystemTetragonal
Mohs Hardness7.5
Specific Gravity4.68
ColorBrown, red, yellow, green, blue
LusterAdamantine
StreakWhite
CleavageNone
FractureConchoidal
Occurrence
Found in igneous and metamorphic rocks. Gem varieties heat-treated to blue. Oldest mineral on Earth (4.4 Ga).