How do I make a mercury glass cake stand?

I guess you would have to make a faux mercury glass cake stand since mercury glass a specific glass.

You can purchase metallic silver spray paint.!

You can glue a clear plate to a clear candle holder then paint it with mirrored spray paint that will make it look like mercury glass. https://amzn.to/2X0R3d2

YouTube will probably have a lot of excellent videos.