Top gem grade
Australian boulder opals of this grade are extremely rare. They score very high in most valuation factors, including, brilliance, colour, pattern and play-of-colour. They often also have a black or very dark body tone.
Australian boulder opals of this grade are extremely rare. They score very high in most valuation factors, including, brilliance, colour, pattern and play-of-colour. They often also have a black or very dark body tone.