For me "chalky" and "astringent" are quite different sensations on my tongue.
Astringent can be rather biting, and unpleasant, depending on the degree. I think some kinds of fruit are astringent if not fully ripe. Perhaps persimmon, Surinam cherry, Monstera Deliciosa, or ?
Chalky feels a bit like a coating on the tongue. I generally find it pleasant in moderation, but I don't know why. It may be a bit like raw, straight-from-the-box cake mix.