How can stibnite form in limestone near hot springs?

Stibnite, the primary ore of antimony, can form in limestone through the action of hot springs. In this process, mineral-rich hydrothermal solutions circulate through the rock, depositing the antimony sulfide ($S{b}_2{S}_3$) as they cool or interact with the environment.1

While the formation of stibnite in limestone is attributed to these hydrothermal processes, it is distinct from the formation of skarns. Skarns occur when high-temperature hydrothermal solutions react with carbonate rocks like limestone or marble to create silicate minerals, typically in close proximity to igneous intrusions. In contrast, stibnite deposits found in limestone are generally associated with the lower-temperature, surface-related activity of hot springs.21