Mood ring

Wernick called the jewelry "magical", and his promotional materials claimed that the color of the pendant or ring is an indicator of the warmth of the wearer's character.

[3] Since Wernick did not patent the invention, other jewelers adopted the idea and began to produce their thermosensitive jewelry.

Soon someone came up with a successful term "mood ring", which was quickly adopted by all manufacturers, including Wernick.

[4] Important producers of "mood rings" were Joshua Reynolds and Maris Ambats; many sources credit them as their inventor.

[5] Reynolds called the rings "a real biofeedback tool" that allows a person to get additional information about their body.