Sulfur exists in nature as a yellow-hued, soft solid. On the Mohs scale of mineral hardness, sulfur only registers a hardness of 1.5 to 2.5, making it a very soft element.
Sulfur has a specific gravity of only 2.0 to 2.1, making this element feel light. The element also has a characteristic pungent smell reminiscent of rotten eggs. Sulfur is used in gunpowder and is a component of fossil fuels. The element can also exist chemically bonded to other elements in compounds such as sulfur dioxide and carbon disulfide. Minerals such as gypsum, celestite and galena all contain sulfur.
Sulfur has six electrons in its outermost energy level, making it a fairly reactive element. It has four stable isotopes that can be found in nature.