by E. Billie Hughes
GemmoRaman-532 • Instrument Review • Lotus Gemology

The difference between a synthetic, treated, or untreated natural gemstone could mean a difference of thousands, even millions of dollars. Thus, it is no wonder that laboratories are becoming more in demand than ever. With treatments become increasingly sophisticated, gemologists and traders search for new tools to help identify stones.

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by Richard W. Hughes
Red Rain • Mozambique Ruby

Is the Mozambique stone the bejesus of bird's blood? Lotus Gemology's resident ruby wallah, Richard Hughes, weighs in on the state of the market and how Mozambique stacks up to historical heavyweights like Burma and Thailand/Cambodia.

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by Lotus Gemology
Oiled Gems Lab Alert • 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.

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by Gustav Tschermak von Seysenegg
Discovery of rutile silk in sapphire

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.

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by E. Billie Hughes
Presidium Synthetic Ruby Identifier

In the lab and marketplace alike, gemologists and gem traders seek to separate natural ruby from synthetic with training and gemological equipment. But what if there was an easier, faster method?

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by Richard W. Hughes & John I. Koivula
Seeing Red • Genetics & Color Vision • Lotus Gemology

Do men and women have the same ability to see red? The answer might shock you.

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by John I. Koivula & Richard W. Hughes
Testing Yellow Sapphire • Passport to Obscurity • Lotus Gemology

The examination of a yellow sapphire provides a lesson in the power of gemological microscopy.

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by Richard W. Hughes, John Koivula & Warren Boyd
Emeralds from Russia • A Closer Look • Lotus Gemology

A brief look at the famous emerald and alexandrite from Russia's Ural Mountain mines.

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by Richard W. Hughes
Pleochroism in Faceted Gems • An Introduction • Lotus Gemology

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.

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