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 (1936). Inspired by the success of the tales, Bazhov continued working on them. The tales "Sinyushka's Well", "Silver Hoof", and "The Demidov Caftans" were finished even before the publication of the first "The Malachite Box" edition. By 1938 the author finished 14 stories. Because of Bazhov's tense relationship with the Communist Party, they were published under two different pen names, either under the name "P. Bragin" or simply under his initials "P. B.". The name of Vasily Hmelinin was usually in the title as well. The first edition of "The Malachite Box" was released in several versions. The first copy