The chapter on ruby and sapphire from Burma (Myanmar) from Richard Hughes' 1997 book, Ruby & Sapphire.

The author makes his first pilgrimage to Burma's Mogok Stone Tract, home of the pigeon's blood ruby.

The issue of gemological nomenclature is one that has been hotly debated for decades, because an attractive name is a crucial part of marketing and selling gemstones. In this article from 1994, Richard Hughes takes a stab at the subject.

In 1991, titanium-diffused blue sapphires reappeared in the Bangkok market after an absence of many years. Touted as "deep diffusion," the stones proved to have no greater color penetration than the original Union Carbide product.

Surface ('bulk') diffusion-treated corundums (SDTCs) created a stir in the Bangkok market in 1990. This article looks at the original patents and continues through the so-called "Deep Diffusion" treatment. Identification methods are discussed, as well as the backroom politics of disclosure. At the end is a quick-reference table summarizing key identifying features of all types of natural, treated and synthetic corundums.

A discussion of brilliance, windows and extinction as they relate to the face-up appearance of colored gemstones. Diagrams demonstrate that extinction is largely a function of cut.

Probably the first opinion piece I ever wrote, it was my take on diamond grading from the standpoint of someone working with colored stones.