Earth Science Laboratory

MINERAL IDENTIFICATION STUDY GUIDE: Non-Silicates (Diagnostic physical properties indicated in italics)
#	Mineral  Name	Chemical Group	Chemical Formula	Mohs H	Color	Streak	Type Cleavage	Luster	Acid Rx	Other Properties
20	galena	sulfides	PbS	2.5	silver-gray	gray	3 dir.- 90o	metallic	H2S	heavy
27	sphalerite	sulfides	ZnS	3.5-4.0	dark brown with yellow streaks	light yellow to brown	6 dir.	resinous to submetallic	H2S on powder	cleavage not always apparent
8	pyrite	sulfides	FeS2	6 - 6.5	pale brassy yellow	brownish black	none	metallic (may be tarnished)	H2S on powder	heavy; scratches glass (unlike chalcopyrite)
21	chalcopyrite	sulfides	CuFeS2	3.5 - 4	brassy yellow	greenish black	none	metallic (often tarnished)	H2S on powder	heavy; always softer than pyrite
36	barite	sulfates	BaSO4	3 - 3.5	white	white	2 dir.	vitreous	none	unusually heavy; cleavage not apparent
30	gypsum, alabaster	sulfates	CaSO4 2H20	2	white	white	none	silky	none	granular/sugary appearance
23	gypsum, selenite	sulfates	CaSO4 2H20	2	transparent, white	white	3 dir. rhombic	vitreous	none	cleavage obvious only in selenite variety
22	gypsum,  satin spar	sulfates	CaSO4 2H20	2	white	white	none	silky	none	fibrous
3	calcite	carbonates	CaCO3	3	colorless, white, yellow	white	3 dir. rhombic	vitreous	CO2 fizzing	transparent calcite shows double refraction
4	halite	halides	NaCl	2	colorless	white	3 dir. - 90o	vitreous	none	tastes salty
25	fluorite	halides	CaF2	4	purple/blue/green/ yellow/clear	white	4 dir.	vitreous	none	cleavage dir. not always apparent
31	graphite	elements	C	1	gray	gray/black	1 dir.	submetallic	none	very soft; platy
16	hematite, specular	oxides	Fe2O3	5.5-6.5	silver to reddish-brown	reddish brown	none	metallic to submetallic	none	non-magnetic; masses of silvery flakes or granules
34	sulfur	elements	S	2.5	yellow	yellow	none	resinous	none	bright yellow masses
29	hematite, massive	oxides	Fe2O3	5.5-6.5	steel-gray to reddish-brown	reddish brown	none	metallic to submetallic	none	non-magnetic; usually no discernible grains
32	magnetite	oxides	Fe3O4	5.5-6.5	black	black	none	metallic	none	strongly magnetic
39	corundum	oxides	Al2O3	9	gray, brown, red, blue, etc.	none	none	dull, vitreous	none	often in barrel shaped crystals; used as gems