choice one correct answer Rocks containing iron, calcium, magnesium, or sodium break down into a) sands and gravels, b) clays Solution Answer:- (b) Clays One types of clay montmorillonite which is hydrated sodium calcium aluminium Magnesium silicate hydroxide. (Na,Ca)0.33(Al,Mg)2Si4O10(OH)2 . nH2O Some other type of clay are Halloysite Illite Vermuculite Talc Palygorskite.