Searching for the source of diamonds in Paraguay

Published
Jun 30 2026
By Becca Beutel
Three men hand-sieving sediments in a small stream within a lush jungle.
Sieving for diamonds and other heavy minerals in a stream of the Capiibary area.

Written in collaboration with Gary Fung. 

This May, Dr. Maya Kopylova and PhD student Gary Fung from the Department of Earth, Ocean and Atmospheric Sciences (EOAS) went on a two week geological excursion to eastern Paraguay to investigate the origin of alluvial diamonds in the Capiibary area, an Atlantic Forest region in northeastern Paraguay. The fieldwork was strenuous, consisting of trekking through the jungle to reach sites over 40 sites where diamonds had previously been recovered, or to potential diamond source areas in upstream tributaries and floodplains to gather clues on where these stones came from. They sieved and panned stream sediments to retrieve heavy mineral concentrates (e.g., zircon, ilmenite and chromite), and eventually, were rewarded with two ~2mm diamonds found on site. Additional diamond samples were purchased from garimpeiros (artisanal miners) to supplement the research. 

Back at UBC, Gary conducts detailed laboratory analyses to reveal the detrital history and provenance of these mysteriously sourced diamonds. By examining their morphology, physical and chemical characteristics, and tiny mineral inclusions trapped during growth deep within the Earth, the research team hopes to identify their source and better understand where in the mantle domain the diamonds originally crystalized. This work, titled “Dual origin of alluvial diamonds from Capiibary, Paraguay”, will be presented at Goldschmidt 2026. 

Three men sitting and one standing all looking al the camera. They are outside, with lush foliage above and behind them, the porch of a home visible as well.
Gary (rightmost) and Roldofol, a local miner, (leftmost) with a Paraguayan family who gave the research team permission to collect samples from the stream on their land. 

The project was conducted in partnership with the Faculty of Engineering of the National University of Asunción (FIUNA). Maya and Gary delivered lectures and met with faculties and students at FIUNA, sharing information about UBC’s geology and geological engineering programs, as well as the fundamentals of diamond characterization and exploration. Gary thanks his collaborators, Dr. Jaime Presser and Prof. Fernando Larroza, and the project funders at EduCanada and the Geological Society of America for their support. He is grateful to many Paraguayans whose hospitality made the fieldwork possible, and who warmly shared chipa guasu (a traditional dish) during their visit!  

Woman with a microphone giving a presentation entitled "Teaching and Research in Earth, Ocean and Atmospheric Sciences at the University of British Columbia."
Dr. Maya Kopylova delivering a lecture on teaching and research in EOAS while visiting FIUNA.