Mood Rings
Mood rings react to your body temperature. The mood ring was invented in 1975 by to inventors Joshua Reynolds and Maris Ambats. The mood rings can also change colour depending on the air temperature around you. but if it can also be also be changed by the air temperature around you that also means that it is not very accurate. The meaning for each colours are violet is if you were feeling happy and green is normal yellow is tense or excited and brown means anxious or nervous.