Tea set. Opaque type of glass ???????

I just picked this set up at Habitat For Humanity Restore., I'm not really into glassware because I know nothing about it. But I was in there the other day and it caught my eye. Then I went back today and it was still there so I bought it. I have never seen this type of glassware before. I asked the volunteer there if she knew anything about and she said that it came in with a lot of really old stuff from an estate.
There are no markings at all on any of the pieces. On the back side of the plates you can see some swirl marks. All of the gold trimis absolutely perfect with no signs of chipping or discoloration.
The forth picture is held up to a light. You can see the light bulb in back of it.
If anyone can tell me what type of glass it is I would appreciate it.
Thanks in advance,
Tony