ZIRCON

Art Nouveau Era blue zircon brooch

Species:  Zircon
​​Mohs Hardness:  6 to 7.5 out of 10
Color:  Nearly all colors.
RI:  1.930 to 1.987
Birefringence:  Can be as high as 0.059 (strong doubling)
SR/DR/AGG:  DR
Clarity Type:  Type II
Optic Character:  Uniaxial positive
Spectrum:  Varies with color
Fluorescence:  Varies
SG:  3.90 to 4.73
Routine Treatments:  None
Additional Enhancements:  Heating

Zircon Facts

Photo courtesy of GIA

Zircon is a natural gem that occurs in an array of attractive colors.

It is often unfairly confused with the mand-made gem:  cubic zirconia.

Zircon, unlike cubic zirconia (which is singly-refractive), has a very high level of birefringence which causes eye-visible doubling.

Zircon is found in many different locations.  Below is a list of the different locations that different colored zircon is found:

BLUE:  Cambodia, Sri Lanka, Myanmar (Burma)
CHAMPAGNE:  Tanzania (Tunduru region)
CHARTREUSE:  Nigeria
COLORLESS:  Cambodia, Sri Lanka
GREEN:  Sri Lanka, Myanmar (Burma), Nigeria, Tanzania
GREY:  Nigeria
ORANGE-BROWN:  Cambodia, Nigeria, Vietnam
PEACHY-PINK:  Australia
PURPLE-PINK:  Tanzania
RASPBERRY:  Tanzania (Tunduru region)
RED:  Tanzania
REDDISH-BROWN:  Vietnam
YELLOW:  Sri Lanka, Tanzania, Nigeria

Zircon is a December birthstone.