Changes

[[Igneous rock]] with over 65% total [[silica]] and over 20% [[quartz]].

'''Acid rocks'' are [[igneous rock]]s with over 65% total [[silica]] and over 20% [[quartz]].

Pellant, p. 250

Pellant, p. 250

=Sources=

==Sources==

*Pellant, Chris. ''The Complete Book of Rocks and Minerals'', Dorling Kindersley Inc.: New York (1995)

*Pellant, Chris. ''The Complete Book of Rocks and Minerals'', Dorling Kindersley Inc.: New York (1995)

[[category:geology]]

[[category:Igneous rocks]]