This is another piece of jewelry from Mary E Fine in the UK that I got a while ago. Someone else actually bought it and then returned it because it was "too bright" - and she sent me a second chance offer. I really love it. I did a little research and I'm fairly sure it must be a natural ruby because created rubies weren't common until later, after 1918.
Here's the ebay description and images:
Victorian 9 Ct Gold 2 Carat Ruby Small Pendant or Charm c1870
A beautiful rich pink ruby has a border of pearls to create this small pendant or charm. It is set in 9 carat yellow gold. The ruby is around 2 carats and is closed back set. Please see below for further details. It appears to have come from a larger piece. The design and craftsmanship date this small pendant or charm to the Victorian period, circa 1870. The pendant or charm is 14mm by 14mm or just under 5/8 inch not including the loop. The ruby is 8mm by 8mm, around 2 carats and tests as ruby. Weight is 1.9g or 0.07oz. Unmarked, tests as 9 carat gold. In very good condition. To the reverse there are two indentations indicating that this piece most likely came from a larger piece. Will be sent with a new quality presentation case.
I'm not sure what it came off of, but it makes a lovely pendant! It's larger than life in the pics, it's only 8mm tall.