Single crystals of sanidine, orthoclase, microcline, oiligoclase, and labradorite, as well as polycrystalline bytownite, were shocked experimentally to peak pressures as high as 45 GPa and subsequently annealed under dry conditions for various times at 800 ¿C, 900 ¿C, and 1000 ¿C. These experiments reveal that alkali feldspars do not change their Al, Si-distribution due to shock alone, but when subjected to shock pressures >22 GPa and then annealed, microcline and orthoclase rapidly transform to sanidine, displaying a highly disordered Al, Si-distribution. High diffusivity of K, Na, and Ca was observed in a labradorite sample shocked to 26 GPa. Subsequent annealing may thus disturb chemical, structural, and isotopic characteristics of shocked minerals and rocks more easily than of unshocked specimens. This is of considerable importance for the interpretation of isotopic age data of impact breccias. Recrystallization textures of annealed diaplectic plagioclase glasses are very distinctive and may be used as a relative measure of the shock pressure experienced by the samples.