Opal
The highly prized Australian opal is one of nature’s true works of art. Recognized as the premiere source, the Lightning Ridge area of New South Wales produces a very finite supply of this phenomenal stone and no two opals are exactly alike. Each masterpiece is a complex palette of colors in blue, green, orange yellow and/or red. As you move the opal around in the light, flashes of color are revealed in the depths of the gem.
Black opals are the most valuable variety of opal and is distinguished by its black or dark ‘body tone’ which allows for the opal’s brilliant and vivid play of color. Of all black opals, those with red tones and patterns in the play of color will command the highest premium. Not all opals display play of color, and they are referred to as common opal. Opal is formed by silica and water over thousands of years. Spheres of silica stack in a regular order, and this internal structure diffracts light so play-of-color can be seen.
Opal is the birthstone for the month of October.
Specifications
Origin: | Australia, Mexico, Ethiopia |
Color: | Colorless, white, gray, bluish gray, brown or black with or without play-of-color |
Species: | Silicate |
Hardness: | 5.0 to 6.5 on Mohs Scale |
Birthstone Month: | October |
Anniversary Year: | 14th |
Refractive Index: | 1.37-1.47 |
Birefringence: | None |
Specific Gravity: | 2.15 (+0.08, -0.90) |