I do not believe the one piece is ceramic. It appears to be cased glass
with a base of opaque (milk white) with a rose colored glass top and
hand painted floral design. Could be English (Stevens & Williams) comes
to mind.
The maker is Dugan Glass and the pattern is Double Stem Rose. This
pattern is quite common in carnival glass and dates to the early 1900s.
Here is a brief history of Dugan Glass complements of Glen Thistlewood
carnival glass historian: The glass fact...
Start with the last name and begin with a google search "glass artist
(last name)." You may have to try different variations on the spelling.
Trying to decipher names etched into glass is a challenge. Your other
option would be to try taking them to ...
These pieces don't quite fit into the expertise of this site. With that
in mind here is what I suggest. They appear to be hand blown art glass.
They appear to made in 1997. I would try to identify the artist
signature (which can be quite a challenge ...
Forgot to mention that your pattern was also produced in various shapes
and in carnival glass. It is a very popular pattern. You have a very
nice set of tumblers.