RIKER BROTHERS Art Nouveau Sapphire & Repousse Gold Bracelet. ca. 1900 Not many people are aware that Newark, New Jersey was a major hub for the manufacture of jewelry from the late 1800's until the 1950's. One of the leading companies, the Riker Brothers, has an early history that dates back to 1846. Their pieces are quite sought after and still remain highly collectible today.