In 2018 the Rijksmuseum acquired a gold ring from the first half of the seventeenth century set with nineteen table-cut diamonds. Although this type of ring appears in several pendant portraits from the Northern Netherlands, physical examples are extremely rare. Only one other example is known aside from the one in the Rijksmuseum’s collection. Archival material and contemporary dictionaries have revealed that in the seventeenth century this type of ring was known as a hoop ring and that it differed from other rings because of its shape. The hoop ring is an uninterrupted circle that became increasingly elaborately decorated in the course of the seventeenth century: with engraved patterns filled with enamel and set all around with pearls or table- and rose-cut diamonds. It can be seen from pendant portraits dating from the first half of the seventeenth century that women usually wore the hoop rings on the index finger of the right hand – the preferred hand and finger on which the wedding rings was worn in the Northern Netherlands in this period. Hoop rings are sometimes noted as trouwringen in estate inventories. However, the term trouwring can refer to both the engagement and to the marriage. For the time being, the function of the recently acquired ring remains unclear, but the placement of many hoop rings on the forefinger discussed in this article makes a connection with marriage likely.