Nanyaseik Ruby — Mogok Stone Tract Material
Nanyaseik Ruby — Mogok Stone Tract Material
Ruby from the Nanyaseik area within the broader Mogok production, with characteristic Mogok colour and fluorescence
A Nanyaseik ruby (also rendered Nan-Hse-Sek) is a ruby from the Nanyaseik deposit within the Mogok Stone Tract in Mandalay Region, Myanmar. Nanyaseik is one of the named workings within the Mogok valley that has produced ruby intermittently since at least the nineteenth century. Stones from this locality share the diagnostic features of Mogok material — fine red colour, low iron, strong fluorescence — and are documented in GIA reports and trade literature as part of the broader Mogok ruby provenance.
The Mogok context
The Mogok Stone Tract is hosted in marble and gneiss of high metamorphic grade. The marble host produces ruby with low iron content, which preserves the strong red fluorescence under ultraviolet excitation that is one of the diagnostic features of Burmese material. Nanyaseik works the same metamorphic geology and produces material with the characteristic Mogok signature: pure red to slightly purplish-red colour, fluorescence under both shortwave and longwave UV, and a trace-element chemistry consistent with marble-hosted corundum.
Production and history
Nanyaseik has been worked through hand-pit and small-scale operations for over a century. Production has been irregular and modest in volume relative to the major Mogok workings (Pyaung Pyin, Kyatpyin, and others) but the deposit has yielded fine-quality stones at intervals. The locality is documented in GIA Gems & Gemology and in trade literature as a recognised Mogok working.
Trade and value
For practical trade purposes, Nanyaseik ruby is sold under 'Mogok' or 'Burmese' provenance designations rather than as a separate locality category. Origin opinions from Gübelin, SSEF, AGL, Lotus Gemology, and GIA typically refer to Mogok at the area level when the analytical data support it; finer location refinement to specific Mogok workings is uncommon on commercial reports. The Nanyaseik designation is more often encountered in trade conversation and dealer notes than on laboratory documents.
Pricing follows Mogok ruby norms: stones with vivid colour, eye-clean clarity, and unheated status above two carats command premium prices, with auction-grade material reaching well into five-figure US dollar per-carat ranges and exceptional examples substantially higher. The Burmese provenance premium over Mozambique and Madagascar ruby is significant and well established.