During the mid-70s, it was no longer necessary to wear your emotions on your sleeve; any appendage would do! Science and marketing merged to unleash one of the biggest fads of all time, the mood ring. Soon, everyone and their mother seemed to be wearing one of these jewelry accessories on their finger, making it easy for the bystander (if the ads were to be believed, at least) to tell what the other person was feeling. (click below to read more)
Mood rings were first introduced in 1975, the creation of two entrepreneurs, Josh Reynolds and Maris Ambats. They simply took liquid crystal and bonded it with quartz so that the ring would change color based on the body temperature of the wearer. The earliest rings were set in precious metals such as silver and gold and fetched hundreds of dollars. The fad really gained steam, however, once more inexpensive versions were offered, making a mood ring affordable to just about anyone.
The liquid crystal inside the mood ring generally displayed a neutral color when it was at the normal body temperature. Fluctuations in that temperature created a whole rainbow of colors, and each ring came with a handy chart to help the wearer (or interested observer) decipher their meanings. This is where science parted ways with marketing, however, as there was really no evidence that any of these colors meant anything specific and often, these charts conflicted a bit with their descriptions. Still, it was pretty much agreed upon that red meant you were agitated, or excited, while blue meant you were calmer and more relaxed (or in the beginning stages of frostbite perhaps). Less vivid colors like yellow and pink meant uncertainty or mixed emotions.
Although mood rings are unlikely to ever surpass the popularity they once enjoyed in the 70s, when millions of these trinkets were sold, the can still be occasionally found in gift and novelty stores to this day. And, as far as fads go, they are right up there with the pet rock in terms of popularity and successful sales.