Exam each mineral carefully, making note of the diagnostic characteristics that make
identification of it possible.
The numbers assigned to the minerals match the numbers
assigned to the mineral specimens included with your VU lab kit.
It will be necessary for
you to learn the name, a diagnostic trait, and the importance of each mineral for a Mineral
Lead sulfide (PbS).
Commonly found in cubic crystals,
cubic cleavage, lead grey color, metallic luster, grey streak,
hardness 2.5, high specific gravity (7.4-7.6), ore of lead.
Zinc sulfide (ZnS).
yellowish brown to brown color, typically resinous luster, typically
yellow streak, hardness 3.5-4, specific gravity 3.9-4.1, powder
treated with warm hydrochloric acid produces rotten egg smell, is
the ore of zinc.
An oxide of iron (Fe
Magnetic, back color,
metallic luster, black streak, hardness 6, specific gravity 5.18, is an
ore of iron.
Iron III oxide (Fe
Granular form dark grey to
black in color, earthy forms rust red, granular metallic
earthy varieties dull luster, reddish streak, hardness 5.5-6.5,
specific gravity 5.26, most important ore of iron.
Mixture of aluminum hydroxides.
Dull to earthy
luster, hardness 1-3, typically pisolitic (round pea-sized grains),
may be claylike, specifi
gravity 2-2.55, ore of aluminum.
Iron sulfide (FeS
Bright yellow color, metallic luster,
greenish black streak, commonly in cubic crystals, hardness 6-6.5,
specific gravity 5.02, ore of iron and source of sulfur for making
Called “Fools Gold” because of its color and luster.
Calcium carbonate (CaCO
Usually white to
colorless, rhombic cleavage, vitreous to earthy luster, crystals
transparent to translucent, may show double refraction (Iceland
Spar), hardness 3, specific gravity 2.72, reacts strongly to
hydrochloric acid, source of lime for use in soil treatment and
manufacture of cement and mortar.
Calcium magnesium carbonate (Ca Mg[CO
Usually pinkish but may be white, brown, or other colors, hardness
3.5-4, specific gravity 2.85, less vigorous reaction with