The plate is 10.25 inches/26.5 cm in diameter.
The inside of the plate is smooth.
The underside has the raised and partially stippled design elements.
I thought it was possibly Early American Pattern Glass, but an expert in EAPG said it was probably English or European...and that a tazza in this pattern was on eBay listed as an antique French tazza, and was signed "France".
Thanks for any help.
Just me,
Gail