Cameo experts, What do I have here? Large Mythological Cameo

Long time no see! I haven't had a ton of time to post on here for a long time. However, I have found something that I am completely stumped on. I have never seen a cameo like this in person before. It is very large and very detailed. It is a mythological depiction of which I don't know. The frame is 14k to 15k gold. Unfortunately it is quite a bit damaged. The cameo appears to be okay and not damaged.... I believe this to be quite old possibly 1850s. Can anyone help? It measures to 2.85 inches across the longest part. It weighs a massive 60 grams!