Creative Ring

Gay Pride ring (a.k.a. "Rainbow ring") - Representing gay pride, usually a band, either set with seven stones, inlaid with seven enameled lines, or set with seven larger stones each in a different colour; the colours representing the Rainbow flag (LGBT movement). In decades past, a stone-set ring worn on the right hand ring finger or the pinky of either hand represented a call for gay equality.
Gimmal ring - Ring made of 2 or 3 hoops that are hinged at the back and meant to interlock and open; popular for betrothals in 16th and 17th century Europe
Iron Ring, a.k.a. Engineer's Ring - Ring worn by American and Canadian engineers, after swearing the Engineer's Oath. This is often in the form of a crudely worked piece of iron; modern rings tend to be sleek steel, some with etched geometric designs. The ring is meant to be worn on the pinky (little) finger of the dominant hand at all times. This ring has been loosely associated with Rudyard Kipling.
Mood ring - A novelty ring which changes color in response to body temperature, using a thermochromic liquid crystal.