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 by critics and enthusiastically received by readers, including the general populace and the more sophisticated Soviet intelligentsia. Bazhov turned into one of the most famous writers in the Soviet Union. Strangers would greet him on the streets. The critics agreed that "never has the labour of miners, stone-cutters, teemers been celebrate in such a way, neither in verses, nor in prose", and that Bazhov managed to show the essence of the professional skill of the miners. Mikhail Batin complimented its uniqueness, and novelty in the contents and in the form. Favourable reviews on "The Malachite Box" appeared in "Uralsky Rabochy"