beryl, emerald, chrysoberyl, alexandrite, Russia, Ural Mountains, Malysheva, gems

Alexandrite, a variety of chrysoberyl, and one of the finest colour-change natural gemstones, may almost be called “the national gemstone of Russia”. This great prestige is based on two facts: its noble name in honour of the Tsarevich Alexander Nikolaevich (the future Tsar Alexander II) and its dazzling colours, green in daylight and red in incandescent light, the military colours of Imperial Russia. Although quantities of facetable quality alexandrite are considerably less than those of emerald, alexandrite is counted among and compared to the “big four” of the gem business: diamond – ruby – sapphire – emerald. In this book the authors present an historical overview of emerald mining in the Urals, the discovery of Russian alexandrites in the Uralian emerald mines, the naming and historical use of alexandrites and their appearance and display in mineralogical museums and the gem trade. Morphology and twinning of rough alexandrite is described for single crystals, single contact twins and cyclic twins (trillings). Mineralogical and gemmological properties are thoroughly explained and numerous photo-micrographs of inclusions and growth patterns in faceted samples are presented.