Gemological information

Gemological information for Zircon
Color	Colorless, Blue, Yellow, Orange, Brown, Violet & Red
Crystal Structure	Tetragonal - 4 sided prisms with pyramidal terminals
Refractive Index	high stones = 1.777 - 1.987
Durability	Fair to good, this decreases with heat treatment
Hardness	6.5 to 7.5
Similar stones	Spessartite, Sphene, Andradite, Sphalerite, Topaz, Tourmaline, Synthetic Rutile, Diamond & Strontiium Titanate
Treatments	Heat Treatment to change color
Country of origin	Sri Lanka, Myanmar, Cambodia, Thailand & Australia
Ultrasonic cleaning	Not safe
Steam cleaning	Not safe
Warm soapy water	Safe
Chemical attack	Avoid
Light sensitivity	Heat treated stones may return to their original color
Heat sensitivity	May change color