Fiber-optic lighting is one of the most useful form of lighting in the gemological laboratory. With it, we are able to see inclusions that would otherwise be invisible.

The optical properties of crystals are intimately related to their crystal structures. This article examines the precise relationship between optic character and sign and crystal structure.

Links to websites related to gemology, gemstones, minerals and jewelry.

Tutorials on the use of gemological instruments.

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The use of Fourier-Transform Infrared Spectroscopy (FTIR) in gem identification, with examples of sapphire & jadeite.

Inclusions are among the most important features for identifying ruby and sapphire. This is the chapter on ruby and sapphire inclusions from Richard Hughes' 1997 book, Ruby & Sapphire.

Ruby & Sapphire  •  A Gemologist's Guide

Richard W. Hughes, with Wimon Manorotkul & E. Billie Hughes  |  2017

Designed as a companion to Ruby & Sapphire: A Collector's Guide, this massive volume is aimed specifically at working gemologists, appraisers and students. Based on Richard W. Hughes' 1997 classic, Ruby & Sapphire, this edition is fully updated. The product of nearly 40 years of firsthand experience and research, it covers every aspect of the subject from A–Z. History, sources, prices, quality analysis, synthetics and treatments, everything is here. With over 1000 photos, maps and illustrations and 3500 references, Ruby & Sapphire—A Gemologist’s Guide represents the most comprehensive book ever written on a single precious stone.

Ruby & Sapphire •  A Gemologist's Guide order page