Cloudy silver

[HeidiAnneli]

Hello! I have enamelled a sterling silver piece but when polishing it, it looks cloudy and I'm really struggling getting it to look clear.

I have used wet and dry as well as my radial disks but it doesn't seem to budge. Thinking this is fire stain from firing it in the kiln but surely that can be sanded off.

Any suggestions appreciated!

Heidi