Feldspar - an overview | ScienceDirect Topics
Figure 3. Photomicrographs of K-feldspar crystals from the Ap horizon of an Aridic Haploboroll (Orthic Brown Haverhill soil) in Saskatchewan, Canada: (a) a K-feldspar crystal with the cross-hatched pattern of maximum microcline of fine sand (50–250 μm) fraction; (b) a K-feldspar crystal, showing two phases of a coarse to very coarse sand (500–2000 μm) fraction.