In 1975, sentiment amongst Americans shifted dramatically as much of the anger and rebellion from the 1960s began to evolve into a desire to calm down and enjoy life as fans of the Brady Bunch and K.C. and the Sunshine Band.
Created by Joshua Reynolds, the rings reacted to changes in body temperature and purported to show a person’s present mood, changing colors of the “jewel” in response (blue showing tranquility, black showing anger or tension and so on.) The popularity of the rings took off in New York City and quickly spread throughout the country as they reflected peoples interest in self-introspectiveness (as often expressed in meditation.)
All fads seem to have a very limited lifespan but the lifespan of the rings was actually fixed, in that the rings crystals would only emit the color changes for a period of two years before they would settle permanently into a shade of black. As such, by 1977 the rings were no longer a hot item and would quickly slip into fad-dom.