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