gunpowder was invented in the 16th century, pyrite was an essential part of the mechanism of early firearms...cracks in crystal rocks such as marble, so that veins of minerals are formed . ◄ A pyrite mirror, dating...this surface . u, tD -·3 se uar Rose quartz is an uncommon form of quartz that is often used in necklaces...any of the mineral's normal industrial uses - as an abrasive or parts of a clock mechanism, for example...""I tD n -· 0 C u, u, "0 :::::s tD _.. An almost transparent crystalline mass of rose quartz |