The term "silicon" is derived from the Latin "silex" meaning hard stone, pebble or flint. As one of the most important rock-forming minerals, silicon comprises 28% of the earth's crust and thus constitutes the second most prevalent element there.
For every kilogram of body weight in the human body, approximately 20mg is silicon, although this value seems to decrease with age. Silicon is an important component of connective tissue and can be found in bones, cartilage, skin, blood vessels, tendons, and ligaments. Silicon is also stored in hair and nails.