Lotus • Articles from Lotus Gemology

A brief description of the color types for ruby and sapphire used at Lotus Gemology.

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.

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.

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.

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

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

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

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.

An examination of the problem of separating pink sapphire and padparadscha from ruby.

The use of Fourier-Transform Infrared Spectroscopy (FTIR) in gem identification, with examples of sapphire & jadeite.