Atmospheric particles can interact with supercooled cloud droplets to initiate cloud glaciation. It is this process that effects a clouds radiative properties, lifetime and also the hydrological cycle . The nature of these particles can range from organics to mineral dusts. Previously it was thought that clay minerals were the most active ice nucleating particles (INP) within mineral dusts. Further studies have unveiled that feldspar, in particularly the potassium feldspars, are the most active INP [2-4]. However the feldspar mineral group is complex and diverse with very little specimens being previously tested. In this study 15 characterised feldspars were tested for their ice nucleating efficiency using an immersion mode technique in µl droplets . The results show that potassium feldspars are the most active minerals of the feldspar group in agreement with previous studies.