FA-WIMB024OB-001-089

Natural Gems Belgium Colored Stone Certification : FA-WIMB024OB-001-089

IDENTIFICATION : Natural orangy brown Winton Matrix Boulder Opal - 24.15 ct - semi round - unheated

Species : Natural Opal
Variety : Boulder Opal

DESCRIPTION

Shape & Cutting Style : semi round cabochon, polished both sides
Measurements : 21.3 x 21.0 x 7.6 mm
Carat Weight : 24.15 Carat
Color : orange and Brown covered Green-Yellow-Violet-Blue Flash
Transparency : Opaque
Origin: Queensland

Birefringence : none
Crystallography : Amorphous
Dispersion : Very low
Luster : Iridescent
Hardness : 6-6.5
Refractive index : 1.37-1.47
Specific gravity : 2.10

COMMENTS :

Optical Effect : Opaliscence (Iridescent)

no indications of heating, no indications of other treatments

Personal Note From Natural Gems Belgium:

This natural winton matrix boulder opal is a good example of Iridescence in boulder opal, showing mainly violet blue and green to yellow tones.
polish grade is fair to good, it is semi round shaped, luster is fair, displaying fair color