5.5 on the Mohs scale.

Myanmar (Burma), Russia, Pakistan, South Africa, Austria, Brazil, Italy, North America, Sri Lanka (Ceylon) and Finland. Star diopside is mainly from India.

Diopside is found in two forms, the black star diopside, and the green emerald-like Chrome diopside.

Diopside is not known to be enhanced.

More information on gemstone enhancements.