G.T. Marsh & Co. (also known as Marsh & Co.) was founded in San Francisco in 1876 by George Turner Marsh, an Australian who had immigrated to America, by way of Japan. 

George Marsh was born in Richmond Australia and when he was 15 his family decided to move to America.  On the journey over they stopped in Japan and the young Marsh fell in love with both the county and culture and persuaded his parents to let him stay. They agreed and his father found him work with a tea import/export firm in Yokohama.  Several years later he joined his family in San Francisco and went on to use his experience and the knowledge he had gained in Japan to open one of the first Asian art galleries in the United States.  G.T.Marsh & Company: Japanese Art Repository opened at 625 Market Street at the Palace Hotel in San Francisco. 

The store specialised in fine antiques, works of art and textiles and quickly flourished as the West embraced Japanese culture and became increasingly fascinated with all things Eastern. Marsh was keen to share his enthusiasm and interest in the Orient with his clients and as his experience and success grew he opened branches in Coronado, Los Angeles, Santa Barbara, and Monterey. 

During the 1930s the firm started to produce their own unique style of jewellery.  These pieces were distinctive for their combined use of industrial looking oxidized steel with precious gems traditionally used in Asia such as jade, pearls and coral. The highly unusual, black patinated steel used in the firm’s jewellery was created by an Italian born jeweller who worked for Marsh. He had an interest in metallurgy and also in shotguns which had led him to experiment with metals and the processes used to help prevent them from rusting.  He treated steel by sandblasting and bluing it, which created a matte finish that contrasted beautifully with polished gold and lustrous gems.

By the turn of the century the company was being run by the third generation of the Marsh family when the decision was taken to close the business in 2001.  Today Marsh jewellery from the 30s, 40s and 50s is rare and extremely collectible and although rarely signed, the pieces are identifiable due to their distinctive appearance and use of materials.