Download Mineral Identification Data Sheet

Mineral Identification Data Sheet
Mineral Group: Sulfides
19
Name &
Formula
Sphalerite
ZnS
(Zn,Fe)S
Colour
Lustre
Streak
Hardness
Cleavage or
Fracture
brown, yellow,
black (if Fe
substitutes for
Zn)
Non-metallic
(unlike most
sulfides) – to
submetallic
brown to
black
(dependant
on Fe
composition)
3.5 – 4
soft
perfect – 6
directions
Metallic
lustrous
black with a
slight green
tinge
6 - 6.5 very
hard (rare
for a sulfide)
none
light or dark
lead gray
metallic
lustrous
black
2.5
soft
perfect – cubic
– 3 directions
at 90°
brass yellowish
(sometimes with
an iridescent
tarnish)
- The colour is
distinctly more
yellowish than
Pyrite
metallic
lustrous
black
3.5 - 4
poor,
conchoidal
fracture
bronzy yellow
metallic
lustrous
black
3.5 - 4
good basal
cleavage is
rarely seen
due to massive
habit
brown to black
with an
iridescent
tarnish
metallic
lustrous
black
3
poor
massive pieces
often show many
cleavage faces
leading to a
sparkling effect
Resinous
Sparkly
20
Pyrite
yellow-to
yellowish gray
FeS2
“Fool’s Gold”
21
Galena
duller colour
than gold
PbS
22
Chalcopyrite
CuFeS2
23
Pyrrhotite
Fe1-xS
24
Bornite
Cu5FeS4
“Peacock Ore”
Mineral Group: Sulfides
Crystal Habit
(draw picture)
crystals
common –
tetrahedral;
massive;
colloform.
Crystal
Drawing
Density
3.9 – 4.2
average
Pyrite often
forms good
crystals, cubes,
pyritohedrons,
Crystals are
usually striated.
5.0 average for
a metallic
Galena forms
cubes,
octahedra and
cubeoctahedrons.
7.2 very heavy
rare – almost
always massive
4.2 – average
for metallics
Special
Properties
often found
with Galena in
carbonate rocks
most common
metallic mineral
Uses
Geological Environment
major ore of Zinc (used to
galvanize steel – a rustproofing
process), Cu + Zn = brass
hydrothermal sulfide ore veins in
igneous rocks; sedimentary
deposits – limestone, dolomite,
marble with Pb; or in veins with
Cu + Pb + Ag
very little
often associated with gold in
quartz ore veins
common in sulfide ores.
major ore of Pb
radiation shielding
once found in gasoline (tetraethyl
lead – anti-knock compound) –
cause pollution
found in sulfide ore veins with Cu
and Zn in igneous and
sedimentary deposits
major ore of Cu
found in sulfide ore veins with
pyrite and other sulfide minerals
crystals are
uncommon
(hexagonal
books)
usually massive
massive, rare
tetrahedral
crystals
4.6 – 4.7–
average for
metallics
It is magnetic
(weaker than
magnetite)
this distinguishes
it from similar
looking Pyrite
and Chalcopyrite
4.9 – 5.3–
average for
metallics
iridescent
tarnish is the
key
distinguishing
property
Pyrrhotite is mined primarily
because it is associated with
pentlandite, a sulfide mineral that
can contain significant amounts of
nickel and cobalt.
Pyrrhotite is an iron sulfide
mineral found in basic igneous
rocks
Bornite is a copper sulfide always
found in association with other
copper minerals – especially
Chalcopyrite.