Sands of the World
Common Minerals and Their Properties 

Mineral	Color	Luster	Streak	Hardness	Other Properties
calcite	colorless	glassy	colorless	3	Crystals often present  Smooth surface Double image may appear when looked through May fizz with vinegar
feldspar	usually pink or white	pearly or white	colorless white	6	One side is smooth and glossy Translucent on edges Small lines on surface
galena	gray	metallic	silver-gray to black	2 -1/2	Breaks into cube-shaped pieces Heavy for its size
graphite	black	dull or metallic	black	1-2	Easily leaves a mark on paper Used inside pencils
hematite	red, brown or black	dull or metallic	light to dark red	5 - 6	Contains approximately 70% iron
magnetite	black	dull or metallic	black	6	Contains iron Attracted by a magnet
muscovite mica	pale to almost colorless	pearly or glassy	colorless	2-1/2 - 3	Splits easily into thin, flat sheets Has a smooth texture Translucent to opague
pyrite	brassy yellow	metallic	greenish black	6 - 6-1/2	Usually forms cube-shaped crystals Brittle, popularly called "fools gold"
quartz	colorless	glassy	colorless	7	Transparent to translucent Often occurs as six-sided (hexagonal) crystals
talc	white	greasy to pearly	gray	1	Feels greasy Ground up to make baby powder

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©  j.carlson-pickering   1998