Lotus • Articles from Lotus Gemology
Oiled Gems Lab Alert • Lotus Gemology
Oiled Gems Lab Alert • Lotus Gemology
- Lotus Gemology
Lotus Gemology warns that oiled rubies, sapphires and spinels are entering the Bangkok wholesale market in increasing numbers. Most, but not all, of these gems are originating from Burma.
Rutile Silk in Sapphire | Discovery in 1878
Rutile Silk in Sapphire | Discovery in 1878
- Gustav Tschermak von Seysenegg
In 1878, the noted Austrian mineralogist, Gustav Tschermak von Seysenegg [1836–1927], was the first to properly identify silk in corundum, finding it to be composed of the mineral rutile (TiO2). An English translation of his landmark paper is included, along with the original German version.
Seeing Red | Genetics & Color Vision | Lotus Gemology
Seeing Red | Genetics & Color Vision | Lotus Gemology
- Richard W. Hughes & John I. Koivula
Do men and women have the same ability to see red? The answer might shock you.
Testing Yellow Sapphire | Passport to Obscurity
Testing Yellow Sapphire | Passport to Obscurity
- John I. Koivula & Richard W. Hughes
The examination of a yellow sapphire provides a lesson in the power of gemological microscopy.
Emerald & Alexandrite from Russia | A Closer Look
Emerald & Alexandrite from Russia | A Closer Look
- Richard W. Hughes, John Koivula & Warren Boyd
A brief look at the famous emerald and alexandrite from Russia's Ural Mountain mines.
Pleochroism in Faceted Gems | An Introduction
Pleochroism in Faceted Gems | An Introduction
- Richard W. Hughes
The phenomenon of pleochroism in doubly refractive (DR) gemstones is described, as it relates to overall color appearance in the context of faceted gems. With strongly pleochroic gems, pleochroism can be seen in faceted gems, even if the table facet is oriented perpendicular to an optic axis. This is because facets change the direction of light as it moves through the gem.
Ruby, Pink Sapphire & Padparadscha | Walking the Line
Ruby, Pink Sapphire & Padparadscha | Walking the Line
- Richard W. Hughes
An examination of the problem of separating pink sapphire and padparadscha from ruby.
FTIR in Gem Testing | FTIR Intrigue
FTIR in Gem Testing | FTIR Intrigue
- Richard W. Hughes, with Loretta Castoro, Hpone-Phyo K. Nyunt & Lore Kiefert
The use of Fourier-Transform Infrared Spectroscopy (FTIR) in gem identification, with examples of sapphire & jadeite.
Hunting the Mother Lode Abroad | Gemological Travel
Hunting the Mother Lode Abroad | Gemological Travel
- Richard W. Hughes & John Koivula
When it comes to gemology, whether it is practiced in the lab or jewelry store, the importance of traveling to the source cannot be emphasized enough. Not only is information more accurate at the source, but the experiences will also make you a better salesperson.
Beryllium Diffusion in Orange Sapphire | The Skin Game
Beryllium Diffusion in Orange Sapphire | The Skin Game
- Richard W. Hughes
The early history of beryllium diffusion in sapphire, starting with the 2001 appearance of large numbers of padparadscha sapphires in the Thai gem market.
Russian Jade Deposits | From Russia with Jade
Russian Jade Deposits | From Russia with Jade
- Richard W. Hughes & Nickolai Kouznetsov
Jadeite jade is a stone intimately associated with Burma (Myanmar). But there are deposits in other countries. This article details Russia's jadeite deposits in the Polar Urals and Khakassia.
Jade in Upper Burma | Heaven and Hell
Jade in Upper Burma | Heaven and Hell
- Richard W. Hughes & Fred Ward
An account of the authors' 1997 visit to Burma's jade mines.
Burma’s Jade Mines | Tracing the Green Line
Burma’s Jade Mines | Tracing the Green Line
- Richard W. Hughes, Olivier Galibert, Mark Smith & Dr. Thet Oo
In 1996, several gemologists set off for Burma's remote jade mines, the first visit by foreigners since the early 1960's. This is the story of their epic journey.
Burmese Sapphire Giants
Burmese Sapphire Giants
- Richard W. Hughes & U Hla Win
A brief history of Burmese (Myanmar) sapphires, along with details of some of the major pieces of yore.
Pigeon's Blood | Pilgrimage to Mogok – Valley of Rubies
Pigeon's Blood | Pilgrimage to Mogok – Valley of Rubies
- Richard W. Hughes
The author makes his first pilgrimage to Burma's Mogok Stone Tract.
Gem Testing with the Spectroscope
Gem Testing with the Spectroscope
- John I. Koivula & Richard W. Hughes
Many gemologists have difficulty mastering the direct-vision spectroscope. This article eases the pain.
History of Chanthaburi & Pailin | Moontown
History of Chanthaburi & Pailin | Moontown
- Richard W. Hughes
The Thai city of Chanthaburi (จันทบุรี) may be small, but it has played an important role in both the history of Thailand and the gem trade. Taking its name from the Sanskrit word for moon ('chan'), this petite town is among the most charming in the Land of Smiles.
Black Prince's Ruby | Blood-Red Souvenir of Conquest | Spinel
Black Prince's Ruby | Blood-Red Souvenir of Conquest | Spinel
- Richard W. Hughes
The history of the Black Prince's Ruby, one of the world's most famous precious stones.
Brilliance, Windows, and Extinction in Gemstones
Brilliance, Windows, and Extinction in Gemstones
- Richard Hughes
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.
Verneuil Synthetic Corundum ID | Dangerous Curves
Verneuil Synthetic Corundum ID | Dangerous Curves
- Richard W. Hughes & John I. Koivula
Virtually all gemologists are aware of the curved growth lines and gas bubbles in Verneuil (flame-fusion) synthetic corundum, but few understand exactly why they occur and how they are distributed in these stones. This article clarifies these important identifying features.