K-Feldspars (KAlSi3O8) are common minerals in the Earth’s crust and play a crucial role as ice nucleators in atmospheric processes. In particular, the well-ordered low-temperature polymorph microcline is a very effective ice nucleator.[1] Understanding their interaction with water is essential for various scientific fields, including atmospheric chemistry and climate science. This study presents experimental atomic-scale imaging of the interaction between K-feldspar and water.[2] We cleaved the mineral in ultra-high vacuum and analyzed the surface using non-contact atomic force microscopy (AFM) and X-ray photoelectron spectroscopy. The surfaces are prone to hydroxylation, exposing arrays of silanol (Si-OH) and aluminol (Al-OH) groups. We studied the onset of ice nucleation by introducing H2O vapor at low temperatures on such hydroxylated surfaces. Ab-initio calculations in tandem with AFM simulations employing the Probe Particle Model [3] helped us interpret our results.