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 a crown, as did Yekaterinburg's coat of arms from 1973 to 1991. The early design of Polevskoy's coat of arms (1981) had an image of the Stone Flower. The current version, as well as the flag of the town, features the Mistress depicted as the golden lizard. The Malachite Casket became the symbol of the Urals. "The Malachite Box" is constantly republished, commented and illustrated. Not all stories are equally popular nowadays. The most popular tales were written between 1936 and 1939. Among the later stories, "A Fragile Twig" (1940), "The Fire-Fairy" (1940), "Tayutka's Mirror" (1941), "Ivanko Krylatko" (1943), "That