Mineral Examples of such minerals are malachite (green) and azurite (blue). In contrast, allochromatic elements in minerals are present in trace amounts as impurities. An example of such a mineral would be the ruby and sapphire varieties of the mineral corundum. The colours of pseudochromatic minerals are the result of interference of light waves. Examples include labradorite and bornite. In addition to simple body colour, minerals can have various other distinctive optical properties, such as play of colours, asterism, chatoyancy, iridescence, tarnish, and pleochroism. Several of these properties involve variability in colour. Play of colour, such as in opal, results in
The Malachite Box them so popular among the adult readers. They were exceptionally popular during the Great Patriotic War. The paperbacks were sent to the front line. The author received fan mail from the soldiers who asked to send them the book. The publication attracted a large number of folklorists, who collected tales near Sysert since 1940s and long after Pavel Bazhov's death. The characters of the Ural Mountains folklore such as the Mistress of the Copper Mountain became very well known after their appearance in Bazhov's "The Malachite Box". Sysert's old coat of arms (1982–2002) featured the Mistress as a lizard with