Enigmatic Silicon Jewelry , which also goes by the name silica and quartz, is a mineral that is abundantly found in the Earth's crust. It is found in a variety of forms and is the second most abundant element on Earth after oxygen. Silica is also an important constituent of rocks, sand, and glass. In addition, silicon also plays an important role when it comes to human health - you must be astounded to know that our bones, our hair, our skin, and even our nails have silica in them.