Creative Ring

Mood ring - A novelty ring which changes color in response to body temperature, using a thermochromic liquid crystal.
Mother's ring - A ring worn by a mother displaying the birthstone of each of her children, and sometimes including those of the mother and father.
Mourning ring - A ring worn in memory of someone who has died. Also commonly called a "memorial ring".
Multi-finger ring - Two or more laterally conjoined rings, designed to be worn on two, three, or four fingers; popularized by hip-hop culture.