What is this? (pic attached)?

I found this at a garage sale and was hoping that maybe it was worth something...? It looked cool anyway...

The picture isn't very good quality, but it's on a gold colored chain and on the top of the thing it says "STVART" or maybe it's "STUART." I'm not sure but then on the right side is a lion standing on its back legs and on the other side is a horse or maybe a unicorn(?) standing on its back legs. I say unicorn because when I googled "Stvart", it showed coat of arms emblems that looked almost identical to this with a few differences and it was unicorn. I haven't come across anything that could help me figure out what this means or is or if its worth anything so I was hoping you guys could help. Thanks!