A. Will leave mark on paper
Argentite Shiny, blackish Lead-gray color 2-2½
to lead gray that tarnishes to
dull black; knife
cuts it smoothly;
heavy; may occur
as masses and
coatings
Galena Grayish black Shiny lead-gray 2½
color; heavy;
cube-shaped
fragments and
crystals
Graphite Black Steel-gray color; 1-2
greasy feel; very
soft; splits into
thin flakes
B. Does not readily leave mark on paper but can be scratched by
ordinary pocket knife
Chalcocite Grayish black Shiny lead-gray 2½-3
color that
tarnishes to dull
black; knife cuts
it smoothly; may
have black sooty
coating; commonly
occurs as compact
or granular masses
Hollandite Black Silvery-gray 4-6
color; may occur
as rounded masses
C. Cannot be scratched by ordinary pocket knife
Braunite Steel gray or Dark steel-gray 6-6½
black color and
submetallic luster
Hematite Dark reddish brown Steel-gray color; 5½-6½
commonly occurs (may be
as granular or softer)
compact masses;
shiny, scaly
variety is
_specular_
hematite; notice
streak
Hollandite Black Silvery-gray 4-6
color; may occur
as rounded masses