Vintage Gemstone

Hello just rediscovered this big stone that is 6.50 ct , I always thought it was suspected amethyst but now I’ve seen purple sapphire I’m not sure anymore, it will be interesting when I finally find out. Not sure when these was popular but there is a few like it. I’m wondering if anyone can tell but the cut what decade it’s from.,I know Victorian & deco are different to modern cuts, but I’m just about getting used to separating native cuts from one’s that look like a expert has cut it.