This is a reposting from approximately four years ago, a white glass CD 247.5 from Russia (the seller was in Belarus) it is not true milk glass, as it does not transmit any light, it is totally opaque, almost like a black glass. So, in a sense I suppose that it could almost be considered as being a white blackglass ;-)

The seller originally believed it to be porcelain, but it didn't look so to me, so I gambled $9 plus 38 shipping, and received this unusual gem. It has a couple of minor base chips, but after cleaning, it became a beautiful snow-white beauty. I have only ever seen one other similar insulator offered for sale, and it was a grimy gray and had significantly more damage.

After cleaning, it looks like this [id=176208442] I tried to emphasize the embossing in this shot.