Ruby, spinel and cobalt blue spinel, chosen at the Sunday market we have traded at since 1990. Photos unedited. Treatments disclosed. Origin named down to the valley.
Low-iron marble makes rubies and spinels that fluoresce in daylight. A morning market run by women who have traded here for thirty years. And the world's only meaningful source of cobalt blue spinel — twenty minutes from our door.
Read the Luc Yen Origin GuidePhuong “Phoenix” Nguyen — second-generation trader. From the ruby-fever years to a remarkable cobalt spinel strike sold at the mine in 2020.
Heated and unheated ruby and sapphire are both natural. What heat really does, the full ladder of corundum treatments, and where the premium is…
How to read a gem lab report: what GIA, Lotus and SSEF actually certify, the treatment wording that moves price, origin opinions, and when…
Why cobalt spinel commands the highest prices in the spinel family: the Fe/Co science from GIA research, Luc Yen sources, rarity, and how to…
New stones from the market, once a month. No noise — just what we found, what it costs, and the story of where it came from.
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