Diamant began as a manufacturer of bicycles and knitting macines in Siegmar-Schonau in 1885. Like many others, they progressed to motorcycles after the turn of the century, following a venture with Elite. The new company became Elite-Diamant. The first machines were single cylinder using their own engines, as well as Fafnir engines. WWI interrupted motorcycle production for the company, but bicycles continued. In the 1920s, they resumed the production of motorcycles and began to use 2 stroke engines from Kuhne. Their 500cc single from the late 1920s featured a unique front suspension arrangement which was well regarded.
In 1928, they were acquired by Opel, but operated independently. As they began the 1930s, they eventually used engines from Fichtel and Sachs as well as JLO. However, competition was stiff, and Diamant never reached anticipated sales levels. Motorcycle production ended in 1940, despite a couple of attempts to revive it later on. Bicycle production remained strong and Diamant went on to become a world leader in the 1950s.