Rachelle Turnier

Rachelle TurnierPhD student, Geoscience

Faculty advisor: John Valley

Rachelle is a Geoscience PhD student studying the crystallization of gem corundum, more commonly known as ruby and sapphire. This mineral is difficult to form but can be found in igneous and metamorphic rocks. Rachelle’s focus is on corundum from igneous and alluvial (gem gravel) deposit samples in Montana and Myanmar, where crystals may have formed in a previous setting and been carried to the surface by the igneous rock. These locations are interesting for a gem researcher, as Montana is the only place in the U.S. where gem corundum is still commercially mined, and Myanmar corundum deposits are famous for having produced some of the best rubies and sapphires – including the four most expensive rubies in the world.

A greater understanding of how corundum forms can potentially refine prospecting methods for new deposits. Rachelle’s work will also help determine the geochemistry of these gems from different deposits, which may help identify the gem’s country of origin by giving researchers another diagnostic tool. “This is important for holding the industry to fair prices and supporting ethical mining practices,” Rachelle explained.

Rachelle came to campus supported by an Advanced Opportunity Fellowship, which she said was instrumental in securing other grants and awards. In her first year as a PhD student, she interned at the Gemological Institute of America. She has gone on to win a number of travel and research grants, including a recent grant from the Geological Society of America and a scholarship from the Tobacco Root Geological Society.