Triangular Ashtray 10" circa 1958, Ruby Jeweltone glaze also listed in catalogs as Rubytone, photos courtesy makeityours-kts on eBay

Note: The above information is for R-1788-A as R-1788 has not been found in a catalog and they are assumed to be the same design. An example marked R-1788-A is not known.

Bottom reads:  ROYAL HAEGER R1788 U.S.A.