Mineral Identification Data Sheet
Mineral Group: Silicates (Common Rock Forming Minerals) and Sulfates
7
Name &
Formula
Phlogopite
Colour
Hardness
Cleavage or
Fracture
shiny
reflective sheets
vitreous
2.5 – 3 (soft)
perfect
1 direction
peel off sheets
with fingernail
red, orange,
pink,brown
usually dull
6 (hard)
good in 2
directions
90° apart
off-white,
grey
usually dull
6 (hard)
good in 2
directions
90° apart
pale olive
green to dark
green
vitreous
6.5 (hard to
very hard)
poor
white,
yellowishwhite,
bluish-white
vitreous to
pearly to dull
3 to 3.5 (soft)
poor
1 direction
vitreous crystals
to pearly
2 (very soft)
crystals have
one good
cleavage
plane
amberbronze
intermediate mica
Mg-rich mica
Lustre
Streak
KMg3AlSi3O10(F,OH)2
8
Orthoclase
(Feldspar)
KAlSi3O8
9
10
Plagioclase
(Feldspar)
Albite
NaAlSi3O8
to
Anorthite
CaAl2Si2O8
Olivine
(Mg,Fe)2SiO4
11
Barite
BaSO4
12
Gypsum
CaSO4∙2H2O
can be any
colour
colourless
crystals,
white, beige
can be any
colour
Mineral Group: Silicates (Common Rock Forming Minerals) and Sulfates
Crystal Habit
(draw picture)
hexagonal
“books”
Crystal
Drawing
Density
Special
Properties
above average
for a nonmetallic mineral
(3.3)
flake off sheets of
mica in hand
sheets are
“elastic/flexible”
Uses
Geological Environment
electrical and heat insulation
found in granites with quartz,
feldspar and hornblende
usually massive,
rare blocky
crystals
average (2.5)
most common
mineral.
unusual “wormy”
perthite intergrowth
no uses
found in felsic rocks with quartz
and mica
usually massive,
rare blocky
crystals
average (2.5)
“record grooves”
from twinning
found in all types of rocks and is
often the main constituent of
intermediate and mafic rocks.
usually vitreous,
sugary grains or
massive
above average
(3.8)
some Labradorite
samples show the
Schiller effect
Peridot gems – August birthstone
found with pyroxenes and serpentines
in ultramafic rock and basalt (never
found with quartz).
There are green olivine beaches in
Hawaii. Oxidizes easily to form
serpentine
massive or
radiating blades
very heavy for a
non-metallic
(4.7)
looks like
calcite but
doesn’t fizz,
heavier and
harder than
gypsum
main ore of barium (to make
paper, glass, rubber);
used for X-raying the digestive
system;
used as drilling mud
usually white
masses;
colourless
crystals –
tabular or
prismatic
2.3 (light)
very soft
CaSO4 is called
Anhydrite or
Alabaster (much
harder and
denser)
Used to make wallboard
(Gyprock) – it is dehydrated to
make it harder an more absorbent
– Ontario is a major producer;
A major evaporate mineral found
with limestone