Named by the Egyptians as the "gem of the sun", Peridot is plentiful and generally inexpensive. Ranging from a transparent yellowish green to greenish yellow, traces of iron are responsible for the color. This lime-green gem is found in irregular nodules that were formed deep inside of the earth and brought to the surface by volcanic activity. Clean with warm, soapy water. Avoid use of ultrasonic and steam cleaner.