Stone	Formula	Group	Other Information
	Crinoidal Limestone	-	Organic	white/grey-contains fossils-forms in shallow seas
	Danburite	CaB2Si2O8	Silicates	a silicate of calcium and boron-may be brown, gold, pink or colourless
	Desert Rose	CaSO42H2O with sand	Sulphates	brown-form of gypsum-forms in deserts
	Diopside	CaMgSi2O6	Silicates	colourless-a pyroxene-may be found in meteorites
	Dioptase	CuSiO2(OH)2	Silicates	green-often found in copper deposits
	Dolomite	CaMg(CO3)2	Carbonates	white-tinted with impurities-resembles limestone
	Dolomitic Rock	-	Sedimentary	white-form of limestone-formed by chemical reaction
	Dumortiorite	Al7(BO3)(SiO4)3O3	Silicates	blue-forms in metamorphic Al rich rocks
	Emerald	Be3Al2Si6O18	Silicates	green-variety of beryl-colour due to Cr
	Epidote	Ca2(Al,Fe)3Si3O12OH	Silicates	black to yellowish green
	Eudiolite	Na4(Ca,Ce)2(Fe,Mn,Y) ZrSi8O22(OH,Cl)2	Silicates	found in nepheline and syenite pegmatites
	Feldspar	x(Al,Si)4O8 x=Ca,K,Na	Silicates	variable colour-can be alkali or plagioclase
	Fire Agate	SiO2	Silicates	usually red-form of chalcedony
	Fire Opal	SiO2nH2O	Oxides	orange-colour due to Fe inclusions-forms in Si rich waters
	Flint	-	Sedimentary	grey/black-may contain fossils-forms on sea floor
	Flourite	CaF2	Halides	colourless-found in hydrothermals-source of F
	Fuchsite	K(Al,Cr)3Si3O10(OH)2	Silicates	green-colour due to Cr oxide impurities-a type of mica
	Gabbro	-	Intru Igneous	speckled grey/black-includes feldspar, quartz
	Galena	PbS	Sulphides	grey-industrial source of lead
	Garnet	Fe3Al2(SiO4)3	Silicates	red-aka red almandines-colour due to Fe
	Gneiss	-	Metamorphic	grey/pink-includes quartz, mica, feldspar
	Granite	-	Intru Igneous	grey/pink/white-includes quartz, feldspar,mica
	Grandiorite	-	Intru Igneous	grey/white-similar to granite but contains less Si
	Green Moonstone	KAlSi3O8	Silicates	orthoclase feldspar
	Green Tourmaline	(NA,Ca)Mg,FeAl(MN,Li)	-	green-colour due to presence of NA
	Greenstone Tuff	-	Extru Igneous	green with black speckles-a pyroclastic
	Grossular Garnet	Ca3Al2Si3O12	Silicates	variable colour-very hard
	Gypsum	CaSO42H2O	Sulphates	colourless-forms by evap. in salt water lakes

Chemical Symbols