Quartz, though, is at least a partial exception to this rule. ... like flint. Chemically, quartz is nearly pure silicon dioxide (SiO 2). When there are no impurities, ...

We have now found means whereby the melting-quality quartz can be replaced satisfactorily by other mineral substances rich in silica, such as flint and quartzite.

Yet at Medzhibozh A, Stepanchuk and his colleague Oleksandr Naumenko came across 24 small fragments of mammoth ivory alongside other artifacts made of flint and quartz. Detailed morphological ...