Accidentally discovered by jeweler Marvin Wernick in the late 1960’s, mood rings, which are encased in a stone made of quartz or clear glass, contain a flat strip thermotropic liquid crystals that are believed to change color dependent on the mood or the emotional state of the subject wearing the ring. Wernick discovered the process when he went on an emergency call with a friend of his who happened to be a doctor. The doctor used a strip of thermotropic material on a young boy’s forehead to check his temperature and gave Wernick the idea for the mood ring.
Even though technical discovery of the mood ring was by Marvin Wernick, credit is most often given to Joshua Reynolds for what became one of the biggest fads of the 1970’s. Reynolds was the first to popularize the rings in 1975 and even though they were a fad in the 70’s, they continually resurface for periods of time throughout the years.
Some people believed the liquid crystals could measure mood through temperature, however this is not possible. There is no proven scientific evidence that mood rings actually display the mood of the ring wearer. The scientific explanation of how mood rings work begins with the thermotropic liquid crystal inside of the ring.
The liquid crystal inside a mood ring is heat sensitive and works like a thermometer. The liquid crystals are calibrated to normal surface body temperature (82°F or 28°C) and show body temperatures that are above the normal surface temperature. A person wears a mood ring and their surface temperature is transported to the liquid crystals through their finger.
When a person’s body temperature increases the temperature of the liquid crystal increases, and takes on a different molecular structure at every temperature. Each molecular structure reflects or absorbs different wavelengths which are responsible for the color change in mood rings. The color of the ring actually changes because of body temperature, not because of mood.
When the liquid crystal was calibrated with body temperature, it was also calibrated for color. Average body temperature displays a blue/green or teal color on the mood ring. The following is a list of all the colors and there corresponding moods, starting with the coldest temperature:
Black: depressed or down, really cold outside or a damaged ring
Brown/Gray: anxious or nervous
Yellow/Amber: tense and excited
Blue Green/Teal: average day and average body temperature
Blue: calm and relaxed
Violet/Purple: happy or passionate