Stone	Formula	Group	Other Information
	Quartz	SiO2	Oxides	colourless-varieties include agate,citrine,rose, smoky,blue
	Quartzite	-	Oxides	variable colour-forms from sand on sea bed-contains quartz
	Red Sandstone	-	Oxides	red/brown-formed from sand grains-colour due to hematite
	Rhodochrosite	MnCO3	Sedimentary	pink-colour due to Mn-displays banding of light & dark pink
	Rhodonite	MnSiO3	Sedimentary	pink to brown-colour due to Mn-a pyroxene
	Rhyolite	-	Carbonates	variable colours-similar to granite-may contain quartz, feldspar
	Rock Crystal	SiO2	Silicates	colourless-variety of quartz-main component of quartzite
	Rose Quartz	SiO2	Oxides	pink-colour due to traces of Mn or Ti oxide
	Rubellite	variable	Silicates	pink to red-a variety of tourmaline-contains boron
	Ruby	Al2O3 with Cr	Oxides	red-belongs to corundum group-colour due to Cr
	Rutilated Quartz	SiO2 with inclusions	Oxides	clear with needle like inclusions of Ti oxide-form of quartz
	Sapphire	Al2O7 with Fe & Ti	Oxides	blue-a form of corundum (like ruby)
	Schorl	Variable	Silicates	black-rich in Fe-a member of the tourmaline family
	Seftonite	SiO2	Oxides	moss green-type of chalcedony
	Selenite	CaSO4 2H2O	Sulphates	transparent form of gypsum
	Serpentine	(Mg,Fe)3 Si 2O5(OH)4	Silicates	green to yellow-named due to it's snake like patterns
	Shattcuckite	Cu5(SiO3)4(OH)2	Silicates	rare copper silicate
	Siderite	FeCO3	Carbonates	yellow to brown-source of Fe
	Silicon Carbide	SiC	Carbides	black-very hard
	Slate	-	Metamorphic	grey to black-forms by alteration of sed. rock-includes quartz
	Smithsonite	ZnCO3	Carbonates	usually white-a carbonate of zinc
	Sodalite	SiO2	Oxides	colourless-a principal component of lapis lazuli
	Spahlerite	Na4Al3Si 3O12Cl	Silicates	colourless-source of alloy coatings
	Spinel	MgAl2O4	Oxides	usually black-name given to a group of rock forming oxide minerals
	Spodumene	ZnS	Sulphides	green-source of Li-lilac variety known as kunzite
	Stauroliite	(Fe,Mg,Zn)2Al9 (Si,Al)4O22(OH)2	Silicates	forms in distinctive cross like shapes
	Stichtite	Mg6Cr2CO3(OH)16 4H2O	Carbonates	lilac or rose pink-similar to barbertonite
	Stilbite	NaCa2Al5S13) O3614H2O	Silicates	a zeolite-has a glassy sheen
	Sugilite	KNa2(Fe,MN, Al2)Li3Si12O30	Silicates	forms in syenite- pink/purple
	Sulphur	S	Native Elements	non-metal-usually bright yellow
	Sunstone	(Na,Ca)Al1-2 Si3-2O8	Silicates	aka oligoclase-a plagioclase feldspar
	Syenite	LiAlSi2O6	Silicates	variable colour-includes feldspars,pyroxene & amphibole

Chemical Symbols