Cohn and Rosenberger was established in 1901 by Emanuel Cohn and Carl Rosenberger, Later incorporated in 1943, they shortened the name to Coro, Inc., combining the first two letters of the two rounders last names.

Founded as an accessories boutique in New York City, Cohn and Rosenberger were businessmen who focused on business operations and growth, but they nevertheless had a good eye for the arts, hiring very talented professional jewelry designers who were allowed to develop their own creative visions at Coro.

Even manufacturing was outsourced until they finally purchased their own facility in Providence, Rhode Island in 1929. This facility grew to be the largest costume jewelry manufacuting operation in the world, using advanced production line technology and employing up to 3500 workers at the peak of operations.

Many talented jewelry designers worked at Coro over the years, and it was the job of Adolph Katz to select from among the competing designs the ones that Coro would manufacture and introduce to the market. He also reviewed some of the many independent designs that were submitted to the company, and he often selected designs from this pool as well for Coro to manufacture. Katz also filed most of the Coro patents including some interesting filings for mechanisms that were used in some of the Coro jewelry designs. One example of a patented mechanism was the Coro Duette, a double clip patented in 1931 that you could combine into a single pin through an innovative interlocking catch.

Designers:

Among the well known jewelry designers who worked at Coro at some point in their careers were Gene Verecchio, Robert Geissman, Massa Raimond, Oscar Placco, and Francois, who specialized in floral pins and went on to found his own jewlery company. Despite this roster of talent, most Coro jewelry is not individually marked with the designer's name and is only marked as the work of the company.

As a result, Coro came to be known for a certain design aesthetic that was largely correlated with the designs that Adolph Katz chose to commission for the company. The company made a wide variety of pieces from figural to floral, and they developed different lines marketed at different price ranges but always with recognizable quality.

The company also expanded overseas, establishing the Corocraft brand in England in 1933 and moving into Canada soon thereafter, and they soon had design stores in most major American cities. Coro made a great deal of patriotic jewelry during the years of World War II including the Emblem of Americas brooch that is quite rare and avidly sought by collectors. They also made jelly belly jewelry with lucite and multi-colored glass cabochons for which they become quite well known, but a style which was pioneered by Trifari. Coro was not above exploiting the design innovations of others, and especially Trifari and Monet, but they also created some unique styles of their own such as the Coro Duette from their own roster of designers.

Vintage jewelry; Corocraft bracelet, 1940

https://www.etsy.com/il-en/listing/199888645/vintage-jewelry-corocraft-bracelet

Richton International Corporation of New York purchased Coro in 1957 and continued production at the Providence factory into the 1970s. They were not well positioned in their manufacturing capabilities to produce the bead styles worn in the 1960s or the simpler goldtone jewelry produced in the 1970s by companies such as Monet and Asian manufacturers. Coro ceased ongoing operations in the U. S. in 1979 and continued

producing jewelry in Canada until the mid 1990s.