Prince's metal
/ˈprɪnsɪz ˌmɛtl/(also Princes' metal) Now historical
noun
An alloy, resembling brass, consisting of about three parts copper and one part zinc, used especially for cheap jewellery.
Origin
Late 17th century; earliest use found in The London Gazette. From the genitive of prince + metal, the metal being so named after its inventor, Prince Rupert of the Rhine. Compare German Prinzmetall, †Prinzenmetall, French métal de prince.