FA-OPPC024WH-001-002

Natural Gems Belgium Colored Stone Certification : FA-OPPC024WH-001-002

IDENTIFICATION : Natural yellow and blue Winton Matrix Boulder Opal - 16.91 ct - free form cabochon - unheated - queensland

Species : Natural Opal
Variety : Boulder Opal

DESCRIPTION

Shape & Cutting Style : Free form cabochon, polished both sides
Measurements : 21.2 x 14.5 x 7.6 mm
Carat Weight : 16.91 Carat
Color : Brown covered blue green yellow purple
Transparency : Opaque
Origin: Queensland

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

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 orangy yellow tones.
polish grade is good, it is free form shaped, luster is good, displaying fair to good color