Silica 
A common mineral component of many sands. Its chemical composition is silicon dioxide (SiO2) and this is usually represented as quartz. It is chemically inert, hard and relatively resistant to weathering.
Silica
A common mineral component of many sands. Its chemical composition is silicon dioxide (SiO2) and this is usually represented as quartz. It is chemically inert, hard and relatively resistant to weathering.