This episode of GeOCHemISTea explores cobalt cycling, critical metals, and why geochemists need to think beyond bulk chemistry to understand how elements behave in surface environments. Sam is joined by Owen Missen, lecturer in environmental geology at the University of Tasmania and researcher with CODES, whose work focuses on the environmental geochemistry and mineralogy of elements like cobalt and tellurium.

The conversation explores why cobalt matters in modern technology, how nanoscale particles are changing the way we think about metal mobility, and what this means for environmental risk around mine waste and legacy sites. Owen also shares insights from Tasmania’s mining legacy, including the Mount Lyell–Macquarie Harbour system, and reflects on why understanding metals at the right scale matters for better mining and environmental decisions.

For this episode we read:

Natural cobalt–manganese oxide nanoparticles: speciation, detection and implications for cobalt cycling (Missen et al., 2024)

Simon Bolster joins GeOCHemISTea to unpack what actuallymakes near-surface geochemistry work in mineral exploration: understanding regolith and landforms before you ever “put dirt in bags.” With four decades in gold exploration, Simon argues that many programs fail not because geochemistry is “bad,” but because sampling and analytical choices do not match the terrain,the cover, or the project stage.

The conversation moves from regolith terrain assessment andmapping as the real starting point, to why “lowest detection limit” is not a substitute for good planning. Simon also breaks down industry “silver bullets” (MMI, calcrete, ultrafines) and why blanket adoption creates false confidence. Finally, he explains how DetectOre upgrades gold from ppb-scale field chemistry into something actionable and fast, by leaching and concentrating gold onto a collector device that can be read by pXRF, enabling real-time decision-making while rigs are still turning.

For this episode we read:

Valuing time and how some of the latest technologies arecompressing time to fast track and de-risk new discoveries and mines (Bolster, 2025)

In this episode of GeOCHemISTea, host Sam Scher engages in a thought-provoking conversation with Professor Mohsen Yahyaei, a mineral processing engineer and director at the Julius Kruttschnitt Mineral Research Center. They explore the impact of geographical differences on mental health, particularly how varying daylight hours can affect mood and productivity. The discussion transitions into the importance of integrating geological and processing data to optimize mineral extraction processes, emphasizing the need for collaboration between geologists and processing engineers to enhance decision-making and reduce waste in mining operations.

As the conversation unfolds, Mohsen shares his journey from mining exploration to mineral processing, highlighting the significance of automation and AI in modern mining practices. He advocates for a holistic approach to mining that considers the entire lifecycle of minerals, from extraction to recycling, and stresses the importance of leveraging existing geological data to improve processing efficiency. The episode concludes with a forward-looking perspective on the future of mining, envisioning a fully integrated system that not only maximizes resource extraction but also prioritizes environmental sustainability and circular economy principles.