
Coro jewelry began production in 1901/1902 in New York. There were approximately 9 designers over the years. Jewelry markings are numerous and distinct depending on the year and designer of a particular piece. After almost 80 years of production, the largest costume jewelry manufacturer closed its doors in 1979.

There are 8 pages of different Coro markings at
Researching Costume Jewelry. My clip earrings purchased in Chicago are marked "Coro" in script writing. According to
Researching Costume Jewelry my earrings are possibly a Coro Original dating back to 1947! The Coro script signature is on the clip back below.