The Journal Of Gemmology

Vols. for July 1964 include Proceedings of the Gemmological Association of Great Britain.

Vols. for July 1964 include Proceedings of the Gemmological Association of Great Britain.

This book provides a lucid introduction to the basics of gemmology. It familiarizes archaeologists, art historians and conservators with the science of gemstones and allows them to understand the basic concepts of their provenance, typology and treatments. Which are the main types of gems? What treatments can be applied? How does one analyse gems? How can gems contribute to archaeometrical research? This volume is written by four experts in the fields of gemmology and archaeometry and addresses both students who need an introduction to this field and professionals who want to refresh their knowledge of the topic. This work is part of a series of introductory texts that deal with a broad range of materials-related topics in archaeometry.

Vols. for July 1964 include Proceedings of the Gemmological Association of Great Britain.

Vols. for July 1964 include Proceedings of the Gemmological Association of Great Britain.

The rapid growth of gemological sciences and mineralogy demands a dictionary such as this for gemologists, mineralogists, geologists, jewel dealers, industry and hobbyists. With some 16,000 comprehensive definitions, supplemented by more than 250 diagrams and figures, this is a one-stop reference to any matter dealing with gems and gemology.

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. Chatoyancy and asterism of alexandrite and chrysoberyl from Russia and Sri Lanka are also described. A further chapter deals with characteristic growth patterns of Russian, other natural and synthetic alexandrites. Colorimetric data of Russian alexandrites and green chrysoberyls are explained using the CIELAB colour space, and the distinction between these varieties is explained. A chapter on trace element chemistry and locality determination rounds off the book. An extensive appendix containing lists of historical names, a time table and numerous references provides valuable information on Russian alexandrites for all researchers in the mineralogical and gemmological fields as well as for gemmological laboratories, jewellers and gem dealers. Consequently, this book, illustrated with more than 200 colour figures and photographs, addresses mineralogists, gemmologists, historians, mineral and gem collectors as well as all members of the gem trade.