The effect of natural mica on the morphology and properties of polyamide 6 (PA-6) nanocomposites was examined. Natural mica (sericite) acquired from a well-known mine in Shimane, Japan was ion-exchanged with an alkyl amine hydrochloride compound. The resulting organomica was extruded with PA-6 using a twin-screw extruder. Quantitative analysis of TEM photomicrographs of the nanocomposite reveal a fairly large average particle length and a higher degree of platelet exfoliation for the natural mica-based nanocomposite compared to the clay version, thus translating into a higher particle aspect ratio. The resulting nanomica/PA-6 composite exhibits a high degree of mica exfoliation and improved thermal mechanical properties.