The term DIAMOND ELEMENT is referring to the element Carbon, which has 6 letters. Carbon is a non-metallic element and is the basis of all known life on Earth. It is also the fourth most abundant element in the universe and the second most abundant element in the human body. Carbon is found in many different forms, including diamonds, graphite, coal, and petroleum. Carbon is an essential element for life and is used in many industries, such as manufacturing, energy production, and medicine.