Lotus • Articles from Lotus Gemology

How does one go about choosing a good gem testing lab? The gemologists at Lotus Gemology provide the following guide to help customers make the best decisions when choosing a good gem testing lab.

A discussion of the literature of jade, with particular emphasis on the most collectable books covering both Chinese jade and jade around the world.

27 February 2019: Sapphires heated with high temperatures and low pressures (~1kbar) first entered the market in 2009, becoming more common since 2016. This article examines the process in detail and looks at the question of whether a separate disclosure is needed for the treatment.

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.

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.

A Burmese sapphire shows a celestial scene both externally and internally.

An included calcite crystal within an unheated Burmese ruby displays dramatic twinning planes.

Surface-reaching growth tubes in a sapphire provide insight into the gem’s origin and treatment history.

A ruby’s surface-reaching cavity is filled with red oil.

The optical properties of crystals are intimately related to their crystal structures. This article examines the precise relationship between optic character and sign and crystal structure.