This thin, ivory-colored, almost iridescent antique Belleek porcelain was first made in 1857 in Ireland, and comes in many patterns including Limpet, Tridacna, Grasses, and most familiarly, Shamrock.
Ott and Brewer and Willets are two of the American firms who produced the antique Belleek-type porcelain beginning in the late 1800's. Both Irish antique Belleek porcelain and American antique Belleek porcelain are examples of Belleek offered here at the Atlanta Antique Gallery website.