1.4-million-year-old bones deepen mystery of who reached Europe first
Researchers also found additional relics like stone tools made from flint and quartz, as well as animal bones displaying cut ...
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Mining And Refining: Quartz, Both Natural And Synthetic
like flint. Chemically, quartz is nearly pure silicon dioxide (SiO 2). When there are no impurities, pure quartz is water-clear and often referred to as “rock crystal”. Impurities can give ...