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.
Myanmar's jadeite mines occupy a privileged place, representing the planet's principal source of fine jadeite jade. This article covers the deposits themselves, along with the cutting, grading and trading of jadeite.
Probably the first opinion piece I ever wrote, it was my take on diamond grading from the standpoint of someone working with colored stones.
Digital Devil #14. An exposé on massive "gem" specimens matched with bogus "appraisals."
A discussion of the definition of padparadscha sapphire, from early to modern times, along with the difficulty in standardizing such definitions.
Part 1 of Chapter 10 from Richard Hughes' 1997 book, Ruby & Sapphire. It covers general principles of judging quality.
Appendix B from Richard Hughes' 1997 book, Ruby & Sapphire, consisting of prices.
A loving look at ruby – the gem of passion – from the standpoint of the connoisseur.
An examination of the problem of separating pink sapphire and padparadscha from ruby.
Sapphire is one of the classic gems. In this article, Lotus Gemology's resident connoisseur casts a discerning eye at the factors that contribute to quality in this legendary precious stone.