Low-temperature heat treatment experiments on Burmese ruby.

Greasy Business • The Ongoing Fraud of Oiled Gems

Hands-on workshop looking at different types of jade.

Richard Hughes examines the historical sources of jade, along with the remarkable renaissance in Chinese jade carving that has occured since the 1990s.

Billie Hughes & Wim Vertriest report the results from their low-temperature heat treatment experiments on Burmese ruby.

A look at the history of color types such as "pigeon's blood" and the difficulties in standardizing these definitions.

A look at the history of gem color types such as "pigeon's blood" and "padparadscha" and the difficulties in standardizing these definitions.

A trip around the world to the major sources of ruby and sapphire, with a particular emphasis on localities that produce the most collectable mineral specimens.

A description of the inclusions found in ruby around the world, including Myanmar, Thailand/Cambodia, Vietnam, Tajikistan, Madagascar and Mozambique.

As with any field, gemology is littered with dogma. In this presentation, Richard Hughes slays more than a few of these sacred gemological cows.

A description of the inclusions found in ruby around the world, including Myanmar, Thailand/Cambodia, Vietnam, Tajikistan, Madagascar and Mozambique.

As with any field, gemology is littered with dogma. In this presentation, Richard Hughes slays more than a few of these sacred gemological cows.

A lecture on the trading and grading of ruby and sapphire, with an emphasis on the fine points of what collectors should look for.

A survey of the gem mines of Tanzania, including Merelani, Songea and Tunduru, based on Richard Hughes' 2007 trip.

An exploration of the places that colored gemstones come from and the manner in which these same gems are marketed by the trade.