The latest expedition took GIA’s field gemologists to Kenya and Tanzania, where they gathered extensive samples of tsavorite, spinel, and sapphire rough. The collection included over 15 kilograms of gem rough, featuring more than 10,000 carats of individual sapphires from Garba Tula in Kenya. The origins of each sample were meticulously verified and recorded.
“Our extensive field gemology program is the foundation of our coloured stone research, identification, and country-of-origin services,” said Tom Moses, GIA’s chief laboratory and research officer. “With over 29,000 verified samples—some comprising several hundred individual stones—and more than one million carats from 20 countries, we have the most complete and detailed database of the chemical, geological, and gemological properties of coloured stones from mining locations around the world.”
During the expedition, the GIA team ventured deep underground with tsavorite and tanzanite miners to document the mining processes. They explored the challenges of balancing artisanal mining with environmental conservation while seeking ways to improve operational efficiency. The team also observed the growing mining activity in the Mahenge region of Tanzania, driven by the rising global demand for spinel.
Over the years, GIA’s field gemology team has visited major ruby, sapphire, emerald, and spinel-producing regions across Asia and Africa. These efforts have resulted in a vast collection of gem samples used for advanced studies and often shared with leading academic institutions to support their research. The collected data forms the basis for GIA’s science-based coloured stone identification and origin report services.
Wim Vertriest, manager of field gemology at the GIA laboratory in Bangkok, highlighted some of the team’s groundbreaking work. “GIA’s gemologists documented the development of the Mozambican ruby mines from their discovery in 2009 to becoming the world’s leading source of ruby. We were also the first foreign gemologists to visit the Ethiopian emerald mines after their discovery in 2016,” he noted.
The information gathered from these expeditions also plays a crucial role in GIA’s educational initiatives. Detailed accounts and research findings are frequently published in the Institute’s professional journal, Gems & Gemology. The comprehensive field gemology program was extensively described in the Winter 2019 edition of the journal.
GIA’s commitment to advancing gemological research continues to set industry benchmarks. The knowledge and insights derived from their field expeditions not only enhance gem identification services but also contribute to the broader understanding of global gem deposits, supporting both industry professionals and academic researchers.
