Lotus • Articles from Lotus Gemology

Intro Image Green Fire | Collecting Books on Emerald

Green Fire | Lotus Gemology's Guide to the Literature of Emerald

Details: Richard W. Hughes

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.

Reference Books on Gemology, Jewelry and Mineralogy

Details: Richard Hughes

A curated list of the most important reference books on gems, gemology, jewelry, mineralogy and allied fields aimed at gemologists, book collectors and researchers.

The Gemologist's Core Library | Classic Books on Gemology, Jewelry and Mineralogy

Details: Richard Hughes

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

Intro Image A heated flux synthetic ruby tested by Lotus Gemology.

Con-juring Ruby | A Heated Flux Synthetic

Details: E. Billie Hughes

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

From Fei Cui to Jadeite and Back | Questions and Answers

Details: Lotus Gemology

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."

Intro Image Fun Down Under • Lenny Cram's Opal Mine • Lotus Gemology

Lenny Cram's Opal Mine | Fun Down Under

Details: Richard W. Hughes

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

Describing Color in Gems | A Fool's Guide

Details: Richard W. Hughes

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.

Intro Image Inclusions in Spinel • An Exercise in Aesthetics

Spinel Inclusions | An Exercise in Aesthetics

Details: E. Billie Hughes, John I. Koivula, Wimon Manorotkul, Nathan Renfro and Richard W. Hughes

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.

Madagascar Sapphire | Low-Temperature Heat Treatment Experiments

Details: E. Billie Hughes and Rosey Perkins

Madagascar has become one of the world’s top sources of fine blue sapphire in recent times. In addition to beautiful untreated material, increasing numbers of treated stones have appeared in the market. Some have been heated to relatively low temperatures, below 1350°C, to lighten their color. To help separate unheated and heated Madagascar sapphire, the authors performed experiments to document the changes they undergo with low-temperature heat treatment in air, which is an oxidizing atmosphere.

Gem Inclusion Pairs | Hyperion Siamese Twins

Details: Lotus Gemology

Why should Hugh Hefner be the only one to enjoy twins? This special Hyperion Inclusion Gallery features images from the Lotus Gemology Hyperion Inclusion Database, but are shown as pairs, all the better to compare one form of beauty with another.

Mogok Revisited | A Brief Stay in Heaven

Details: E. Billie Hughes

An account of a 2013 visit to Mogok – Myanmar's fairy-tale wonderland.

Intro Image Downtown: Gem hunting in Central & Southern Tanzania | Lotus Gemology

Downtown | Gem Hunting in Tanzania

Details: Richard W. Hughes & Vincent Pardieu

Since the late 1960's, East Africa has been home to some of planet earth's greatest gem discoveries. And yet, little has been written about certain of these finds. In the autumn of 2007, the authors set out to fill in the gaps, specifically regarding Tanzania's Mahenge, Songea and Tunduru regions.

Intro Image Ownership of Words | An Essay on Padparadscha Sapphire

Padparadscha Sapphire & the Ownership of Words

Details: Richard W. Hughes

A discussion of the definition of padparadscha sapphire, from early to modern times, along with the difficulty in standardizing such definitions.

Intro Image Oiled Spinel • A Shocking Revelation

Oiled Spinel & Tanzanite | Shocking Revelations

Details: Richard W. Hughes

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.

Intro Image Betwixt Two Worlds: A Search for Gemology in the 21st Century

Gemology in the 21st Century | Betwixt Two Worlds

Details: John L. Emmett & Richard W. Hughes

Traditional gemology considers itself a science, but typically omits a key element of the scientific method. And is gemology simply a science, or something more? Read on to learn the answer…

gemology

Intro Image Following the Silk Road | Rutile in Corundum

Rutile in Corundum | Following the Silk Road

Details: John I. Koivula & Richard W. Hughes

A discussion of rutile silk in corundum and its use in detecting artificial heat treatment. Careful examination of these "silk" inclusions can provide vital clues to unmask heated gems.

Detecting Corundum Fillers with the Long-Wave UV Torch

Details: E. Billie Hughes

There are many benefits to using a long-wave UV torch when testing ruby and sapphire. Here are a few examples.

The Hardness of Fei Cui Jade | A Gemological Perspective

Details: Kaylan Khourie

Jade has a long and varied nomenclatural history, with its definition altered in the current age for practical and cultural reasons. This paper examines the hardness of "fei cui" (pyroxene jade) and presents the findings in a simplified format based on empirical evidence and theoretical principles, while also considering the jade hardness data available in literature.

Yellow Sapphires with Unstable Color

Details: E. Billie Hughes

Some yellow sapphires contain unstable color centers. The following discussion outlines case studies of stones that faded after testing in the lab, and how color may be restored.

Intro Image A Canary in the Ruby Mine • Low-Temperature Heat Treatment Experiments on Burmese Ruby

Canary in the Ruby Mine | Low-Temperature Heating of Burmese Ruby

Details: E. Billie Hughes & Wim Vertriest

Detection of heat treatment below 1200°C in ruby and sapphire can present challenges to gemologists. In this study, the authors heated Burmese ruby samples and detailed the features that help in the detection of heat treatment.