Horst Kunzmann operated as a jeweler in Pforzheim, Germany from around 1930 to around 1950.   Pieces produced often were diamond studded and retro in style consisting of all types of jewelry from earrings to rings and pendants.  The typical hallmark for Kunzmann was an HK yet Kunzmann employed a host of other craftsman.  He was one of the few companies that allowed his employees to manufacture their signatures and hallmarks on pieces they crafted under his brand, something well ahead of the time.  The other hallmarks remain a mystery as we do not know the craftsman but include an F in a circle, R, RI, and RO.  Should you have further information on Kunzmann jewelry please let us know!