Lotus Gemology is an independent laboratory in Bangkok established by Richard W. Hughes, E. Billie Hughes and Wimon Manorotkul. It specialises in the identification, origin determination and treatment classification of ruby, sapphire and spinel, and has become one of the most cited laboratories in the contemporary coloured-stone trade. The lab's reports are accepted by the major auction houses and by specialist dealers as carrying significant weight on the questions of origin and heat.

Methodology

Lotus uses standard gemmological microscopy and spectroscopy supplemented by Raman, FTIR, UV-Vis-NIR and laser-ablation ICP-MS for trace-element fingerprinting. Origin determinations rest on a combined reading of inclusions, trace-element chemistry and absorption spectra against the laboratory's reference set, and are issued only where the body of evidence supports a confident call. Where evidence is mixed, the laboratory states origin as inconclusive rather than offering a forced determination.

The Hughes legacy

Richard W. Hughes is the author of the standard reference works on ruby and sapphire (most recently Ruby and Sapphire: A Gemologist's Guide, 2017) and has spent four decades documenting deposits in Burma, Sri Lanka, Mozambique, Madagascar, Vietnam and elsewhere. The laboratory's reference collection of stones and inclusion images draws directly on that fieldwork, which is one reason its calls on Burmese versus Mozambican ruby, or on Kashmir versus Madagascar sapphire, are taken seriously by the trade.

Heat-treatment language

Lotus is also notable for its disclosure framework on heat treatment, which uses the H-letter system - H, H(a), H(b), H(c) - to distinguish unheated from various intensities of heat and the presence of residues. This convention is treated separately in this dictionary under each H-code entry.

In the market

A Lotus report is not the only credential in the trade, but it is one of three or four that materially move price on a high-end ruby or sapphire, alongside Gübelin, SSEF and AGL. For dealers and collectors at the very top of the market, having more than one of these credentials on a stone is increasingly the norm.