Lotus • Articles from Lotus Gemology

The following is a genuine conversation I had with ChatGPT in May 2025.

Although many emerald deposits also produce alexandrite, particularly those formed in association with mica-rich schist, it is rare that both gems are found in such a close association that they can be fashioned into a single stone. This article details the examination of one such piece, reportedly originating from a deposit in Malysheva, Russia.

Welcome to the world of green fire — a curated list of the most important reference books and papers on emeralds from around the world, including Colombia, Russia, Zambia, Brazil, Zimbabwe, Afghanistan, Pakistan, and more.

To the jeweler, spinel is famous for its vivid colors. But for the gemologist, this gem is unlike any other. Its extreme hardness allows a fine polish. Couple this with single refraction, which eliminates the image blurring found in most other gems, and a varied landscape of inclusion subjects, and the result is an unparalleled canvas of delight for the photomicrographic artist.

When a red spinel and a tanzanite were submitted for testing, oil was found in the fissures. Removal of the oil resulted in a startling deterioration in clarity.

A curated list of the most important books on gems, gemology, jewelry, mineralogy and allied fields.

Distracting features in this ruby could easily cause gemologists to misidentify the stone. Learn more about how we unmasked this tricky synthetic.

Recent studies show that the gem known throughout the non-Chinese world as "jadeite" jade is actually a rock composed of three major mineral components – jadeite, omphacite and kosmochlor. These components grow in a submicroscopic aggregate with grains so small that normal lab instruments cannot easily determine the true composition. As a result, China's gem trade has adopted the traditional term "fei cui" (pronounced 'fay choy') to cover all the pyroxene jades. Lotus Gemology has done the same starting on 1 July 2023, dropping the names jadeite/omphacite/kosmochlor in favor of the scientifically more correct "fei cui."

The believe-it-or-not story of Australia's Lenny Cram and his opal mine in a mason jar.

Color types such as "pigeon's blood," "Paraíba" and "cobalt blue" have become wildly popular in the gem trade. But there is a vast difference between coining such terms and applying them in a way that is both consistent and logical. Richard Hughes casts a critical eye on the subject.