Strange Solid Silver online Ring Hallmarked....made in 1900

This is one of the many pieces of 'strange' jewellery I have in my collection!

I have no idea what the shape is supposed to represent/symbolise. I've tried researching it and come up with nothing so if anyone can enlighten me on it, it would be great.

It is solid silver with hallmarks....the makers are 'S.C'....Lion Rampant, Edinburgh Castle (I think), and the letter 'D' which is 1900.

I have photographed as best I can and the areas that look like the ring has split aren't splits as the ring is solid silver and not hollow.

Ring size is US 8.....UK P1/2 online