The Fabrication of Plagioclase Feldspar Microdevices: An Experimental Tool for Pore‐Scale Mineral Dissolution Studies

Abstract

AbstractPore‐scale mineral dissolution reactions are of fundamental importance for sustaining life and determining the fate of chemicals in Earth's near‐surface environments. However, experimental investigations are largely limited to macroscopic approaches due to difficulties in controlling and observing geochemical processes at the pore scale. Here, we present an experimental method using both femtosecond laser ablation and hydrofluoric (HF) etching techniques to fabricate reactive microdevices in a natural silicate mineral, anorthite. The femtosecond laser minimizes damage to the mineral during ablation and HF etching successfully removes a thin amorphous layer induced by laser irradiation. Anorthite dissolution rates under far‐from‐equilibrium conditions (10−8.14 to 10−8.43 mol m−2 s−1), quantified by total calcium flux from the microfluidic device, correspond to previous laboratory‐measured rates also measured under far‐from‐equilibrium conditions, thereby supporting the reactive mineral microdevice as a valuable tool for mineral dissolution studies.