Zircon
Gemstone
Zircon is a mineral belonging to the group of nesosilicates and is a source of the metal zirconium. Its chemical name is zirconium(IV) silicate, and its corresponding chemical formula is ZrSiO₄. Wikipedia
Chemical formula: ZrSiO₄
Hardness (Mohs hardness scale): ≥ 7.5
Refractive index: 1.93 – 1.987
Age: 4.404 billion years
Category: Nesosilicates
Crystal habit: tabular to prismatic crystals, irregular grains, massive