Here's a well-worn, counterstamped quarter from the '49ers California gold rush era. The reverse is equally worn and somewhat flattened from the stamping.

There are some 80 of the Polhemus-stamped coins known on various US and foreign coins. This is a relatively large number in comparison to most surviving counterstamps. The latest host coin recorded is dated 1857. Here are the notes from my database ....
JAMES LOZIER POLHEMUS WAS BORN IN 1825 IN NY CITY, BRUNK REPORTS. HE SAILED ON THE ORPHEUS TO CALIFORNIA IN 1849 AND ESTABLISHED A PHARMACY IN 1850; REMAINING AT THE J STREET ADDRESS UNTIL HIS DEATH IN 1866. AN 1859 DIRECTORY LISTS HIM AS A WHOLESALE AND RETAIL DRUGGIST. HIS WIFE CONTINUED THE BUSINESS UNTIL 1874. ONE OF HIS C/S'd $20 GOLD PIECES, RECOVERED FROM THE WRECK OF THE S.S. CENTRAL AMERICA, SOLD FOR $48k IN 2001. BRUNK SAYS THAT POLHEMUS WAS OPEN FOR BUSINESS AT ALL HOURS, SELLING AT COST TO INDIGENTS; THIS, STAMPING COINS THAT PASSED THROUGH HIS TILL.Here's a drawing of the Polhemus drug/apothecary store ....

Here's one of his advertisements, pictured in an 1863 directory ....

Counterstamps like this one utilized by Polhemus are often referred to as "logo stamps" which incorporate business information beyond the issuer's name. Counterstamps that utilize pictorial images, like this druggist's mortar & pestle, typically add to the desirability of a piece.