corundum, inclusions.5, Burma.12, Sri Lanka.12, gems

Gübelin examines the nature and gemological significance of mineral inclusions in gemstones, emphasizing that inclusions are integral records of the conditions under which their host crystals formed. The two-part article discusses the identification, morphology, and genetic relationships of included minerals and explains how their crystal form, orientation, alteration, and association with other internal features can provide evidence concerning the origin and geological history of a gemstone. Numerous photomicrographs, including color plates, illustrate characteristic mineral inclusions in important gem species. Particular attention is given to the value of inclusions in distinguishing natural gemstones and in determining geographic or geological origin where sufficiently diagnostic inclusion assemblages occur. The study demonstrates the importance of systematic inclusion microscopy both as a practical gemological tool and as a means of investigating gemstone genesis.