Sand to wafers… Fortunately, there is no shortage of raw material. Silicon is the second most common element in the earth’s crust, comprising about 26% and exceeded only by oxygen at 49%. But silicon does not occur naturally in the pure form needed for electronic applications, for which it must contain less than one in a billion non-silicon atoms. The starting material really is sand. Not just any sand, but silica sand, specially quarried for this purpose and having concentrations of quartz (silicon dioxide) as high as 95%.