Black Onyx Value
The International Gem Society (IGS) has a list of businesses offering gemstone appraisal services.
Black Onyx Information
|Is a Variety of||Chalcedony|
|Refractive Index||1.544 - 1.553|
|Special Care Instructions||None|
Onyx is banded chalcedony that is found in many different colors including commonly black and white.