Victorian Carved Pink Angel Skin Coral Or Conch Shell Solid 9k Gold Filigree Cameo Brooch circa 1890

Circa 1890 intricately carved, large Cameo depicting Orpheus with his Lyre It is very thin and I am unsure if it is a natural characteristic of the shell or a minor blemish of some sort. Whatever it is, it does not impact the structural integrity of the piece. It has been acid tested and was determined to be 9 Karat Gold (10K acid solution dissolved very slowly in comparison to the 14K acid solution which dissolved metal on touchstone immediately). Total weight is 19 grams. The picture of acid test was taken after 10 seconds. It also has passed the magnet test. T. Measurements are 52 mm. by 42 mm. The great Antique condition.