Wimon Manorotkul

  • Developing a comprehensive colored stone grading system has been the dream of gemologists since the late 1970's, but despite a number of valient attempts, we are no closer to the goal today than we were four decades ago. This article examines the various problems of colored stone grading, explaining why the challenges are at least an order of magnitude greater than the grading of diamonds.

  • The history of the Lao sapphire mines at Ban Huay Xai is detailed, along with modern mining by Hong Kong based Sino Resources Mining Corp. Ltd. from 2006–2012.

Back to top