Is it true that ';rock forming minerals'; is the mineral that forms a majority of a particular rock?

Most rocks are called by a name that is more likely indicative of their grain size than their chemical composition as found in the mineral constituents of their origins. Hence, we have rocks, i.e., sands, shales, conglomerates, limestones, etc., none of which mentions anything about the minerals that comprise the rocks.





The phrase I think you are looking for is that there are a limited number of minerals that form the majority of rock types. These are called ';rock forming minerals'; because of their abundance in the petrology of rocks.





Only a dozen or so minerals account for the vast volume of the world's rocks.


Here are the minerals and their approximate chemical composition:


Plagioclase feldspar; NaAlSi3O8 to CaAl2Si2O8 (continuous series)


Potassium feldspar; KAlSi3O8


Quartz; SiO2


Pyroxene; (Mg,Fe)2Si2O6 (enstatite series) and Ca(Mg,Fe)Si2O6 (augite)


Biotite; K(Fe,Mg)3AlSi3O10(OH)2


Muscovite; KAl2(Si3Al)O10(OH,F)2


Hornblende; (Ca,Na)2鈥?(Mg,Fe,Al)5[(Si,Al)8O22](OH)2


Olivine; (Fe,Mg)2SiO4


Magnetite; Fe3O4


Pyrite; FeS2


Garnet; (Ca,Mg,Fe2+)3(Al,Fe3+)2Si3O12


Calcite; CaCO3


Dolomite; CaMg(CO3)2Is it true that ';rock forming minerals'; is the mineral that forms a majority of a particular rock?
minerals do form rocks but a mineral is one substance


and a rock has many different minerals in it.