Very interesting 18.6 mm x 13.1 mm oval matrix opals bezel set with a solid gold back. Matrix opals are a type of boulder opal found as part of the host boulder ironstone. They contain opal randomly distributed throughout the rock. The ironstone with the precious opal is cut as one piece. These remind me of the earth with beautiful blue and green highlights running through. The backs are posts and hallmarked by the artist. Approximately 3/4 inch x 1/2 inch. 

Appraisal value: $725