Rare plate from China beautiful design in laid with gold colour and dark blue

I have no details on history or where it came from. It was on the wall in my mother's house about 15 years ago and I can't remember how long it was there.

On the back there are some painted letters and a stamp which we can just make out to read'improved stone China' I'd say the finish isn't perfect and some gold detail has rubbed off. If you'd like more photos please ask or if you can give us some history that would be great! Approx size 9.5" diameter & stands 1.25" high.