Here is a growing list of “marks” that will assist in dating an antique or collectible. Keep in mind that Country of Origin Labeling (COOL), manufacturer’s dating procedures and/or the evolution of a company’s logo or maker’s mark (size, color, etc.) can be used as a pretty reliable foundation for dating an antique or collectible, BUT–it is not definitive. There are always exceptions to the rule. Following are a few common examples of some “dating” information.

List of marks and markings:

Occupied Japan: about 1945 to 1952.

U.S. Zone: about 1945 to 1950.

Rookwood Pottery: 1886 to 1967. The logo is conjoined RP with the R reversed. An RP only reflects circa 1886. A “flame” was added for every year afterward, through 1900. Hence, a mark with 4 flames would be circa 1890 (RP + 4 flames = 1890 OR 1886 + 4 = 1890). After 1900, roman numerals were added under the mark to denote the year. So an RP mark with fourteen flames and the roman numerals below it of XXI, would be 1921.