IDENTIFYING MINERALS
IDENTIFYING
MINERALS
COLOR
The way a mineral interacts
with light
Some minerals always have
the same color
Some minerals have a range
of colors
STREAK
The color of the powder
produced by the mineral
Determined by scraping
mineral across a ceramic
plate
Luster
The way a mineral scatters
light
Distinguish between
metallic and non metallic
Hardness
Measure of a mineral’s
ability to resist scratching
Represents the strength of
the bonds
Hard minerals can scratch
soft minerals, but soft
minerals cannot scratch
hard ones
Mohs Hardness Scale : 1 -10
1 =
10 = Diamond –
hardest
Talc -
softest
Crystal Habit
Preferred crystal shape that
forms when a mineral grows
unimpeded
Breakage
How a mineral breaks
depending on the
arrangement of atoms
2 types:
Cleavage
Fracture
Cleavage: mineral breaks along
weak bonds and forms distinct
flat, smooth (planar) surfaces
Fracture: when bonding is
equally strong in all directions,
mineral breaks in an irregular
or curved way
Specific Gravity
The density of a mineral as
compared to the density of
water
Estimate by lifting specimen
Density of pure water
1 g/cm³
Magnetism
Attracts or is attracted to a
magnet
Feel
Certain minerals feel
slippery or greasy
Weak bonds allow atoms to
slide past each other
Taste
A chemical property,
determined by the presence
of certain elements
NEVER TASTE UNLESS
INSTRUCTED TO DO SO!
Odor
A few minerals have a
distinctive odor
Reaction with HCl
Minerals containing a
carbonate anion fizz when
dilute hydrochloric acid is
dropped on them