metallic and their characteristic properties, for identification

Some

Minerals and their
Characteristic Properties

NAME FORMULA	HABIT	LUSTRE S.g.	USUAL COLOUR/ STREAK	HARDNESS CLEAVAGE	OTHER PROPERTIES	OCCURRENCE USES
Galena PbS	cubic crystals	metallic 7.5	silver-grey grey-black	2.5 3; perfect cubic cleavage		vein mineral, often with calcite, fluorspar and barites cheif source of lead (Pb).
Haematite Fe₂O₃	reniform aggregate habit	earthy 5	Red-brown red-brown	5.5 to 6.5 2 poor cleavages	sub-conchoidal or uneven fracture	often in limestones as a relacement minerals, also in metamorfphic deposites, ironstones and as both thin veins and cement in sandstones eg. the New Red Sandstone iron ore and used as a pigment in paint 'Red Ochre'
Pyrite FeS₂	cubic crystals, or as pentagonal dodecahedral crystals. Also as nodules with an internal structure of radiating needles, also as crystalline masses	metallic 5.0	brass-yellow black	6 - 6.5 no cleavage	cubic crystals often have striated faces, conchoidal fracture, sparks when struck with geological hammer pyrite = fire mineral. smells sulphurous when rubbed on a streak plate	occurs as free crystals or nodules in coal, clay and shales, also in veins formerly source of sulphur, used to make sulphuric acid (native sulphur now main source).
Sphalerite (aka zinc blende, black jack) ZnS	usually massive aggregates, also tetrahedral crystals	resinous, sometimes brilliant or adamantine on fresh surfaces 4.0	brown or black pale yellow	3.5 - 4 perfect cleavage in 6 directions	smells sulphurous when rubbed on a streak plate	vein mineral chief source of [non-corrosive] zinc, used for galvanisation of iron
Chalcopyrite CuFeS₂	octohedral and tetrahedral crystals	metallic 4.1 - 4.3	brass-yellow black or greenish-black	3.5 - 4.0 indistinct		ore mineral