antique art deco aquamarine sterling silver ring

This is a nice antique sterling silver aquamarine ring that has an emerald cut blue green stone I believe is a good old aquamarine- very vivid! Its signed SJ in a oval C shape with a little hook on it and sterling. It is a size 6 - 6.25.

Great patina.

My instinct says this ring is turn of the century - 1920.

Nice old ring.

I was advised that this might be a blue spinel but because I have not had it tested - I am not sure.

Either way, the color of the stone is intense! thank you