A. Can be scratched by a fingernail
Gypsum White Reddish; soft; 2
occurs as
crystals or as
fibrous,
granular,
compact, or
earthy masses
Hematite Dark reddish brown Brownish-red 1+
color; soft and
earthy
Sulfur White or pale Reddish; will 1½-2½
yellow burn with blue
flame; commonly
found as
crystals, crusts,
or grains
B. Cannot be scratched by a fingernail but can be scratched by a copper
penny
Anhydrite White Pinkish tint; 3-3½
commonly occurs
as sugary-looking
masses
Barite White Pinkish tint; 3-3½
rather heavy;
cleavage
fragments may be
flat and slab-like
Calcite White Pink color; 3
dilute
hydrochloric acid
fizzes on
calcite; perfect
cleavage in 3
directions gives
rhomb-shaped
fragments
Cinnabar Dark red Dark red or 2½
bright
yellowish-red
color; shiny,
brilliant luster
when pure; dull
and earthy when
impure; heavy
Halite White Reddish tint; 2½
salty taste;
dissolves in
water;
cube-shaped
cleavage fragments
Sulfur White or pale Reddish; will 1½-2½
yellow burn with blue
flame; commonly
found as
crystals, crusts,
or grains
C. Cannot be scratched by a copper penny but can be scratched by an
ordinary pocket knife
Anhydrite White Pinkish tint; 3-3½
commonly occurs
as sugary-looking
masses
Barite White Pinkish tint; 3-3½
rather heavy;
cleavage
fragments may
look flat and
slab-like
Dolomite White Pink color; 3½-4
commonly occurs
as granular
masses and as
rhomb-shaped
crystals; dilute
hydrochloric acid
may fizz slightly
on dolomite
Fluorite White Pink color; 4
cleavage in 4
directions can
give fragments
that are shaped
like octahedrons;
crystals commonly
cubes
Opal White Reddish color; 5-6
curved,
conchoidal
fracture; may
appear glassy,
greasy, resinous,
or dull
D. Cannot be scratched by an ordinary pocket knife but can be scratched
by quartz
Feldspar White Glassy or pearly 6
luster; good
cleavage in 2
directions that
meet at an angle
of 90° or near 90°
Garnet White Commonly occurs 6½-7
as crystals
Opal White Reddish color; 5-6
curved,
conchoidal
fracture; may
appear glassy,
greasy, resinous,
or dull
Quartz White Curved, 7
conchoidal
fracture; occurs
as _rose quartz_,
as pink _chert_,
and as _agate_
and _jasper_