aluminium, oxygen, and have the general formula Mn+ 1/n(AlO 2)− (SiO 2) x･yH 2O where Mn+ 1/n is either a metal ion or H+. The term was originally coined...

flows and within lava tubes. Weathering on the silicic rocks has yielded zeoliths. The chemical composition of the erupted rocks is not steady, with an increase...

and pestles, anthropomorphic figurines (notably the "Idol of Iguape"), Zeoliths resembling fish, birds, mammals, and other animals, lithic ornaments (tembetás...