8. Mineral
•formed through geological processes
•solid with an orderly crystalline
structure
•with definite chemical composition and specific
physical properties
•a homogenous, naturally occurring
inorganic substance
11. LUSTER
It is the quality and intensity of reflected light
exhibited by the mineral
•a. Metallic – generally opaque and exhibits a
resplendent shine similar to a polished metal
•b. Non-metallic – vitreous (glassy), adamantine
(brilliant/diamond-like), resinous, silky, pearly,
dull
(earthy), greasy, among others.
14. HARDNESS
It is a measure of the resistance of a mineral
(not specifically surface) to abrasion.
measured by scratching the mineral against
another substance of known hardness on the
Mohs Hardness Scale
designed by German geologist/mineralogist
Friedrich Mohs in 1812
15. Why Mohs Scale?
Easy
The test can be done
anywhere, anytime, as long as
there is sufficient light to see
scratches.
The test can be done
anywhere, anytime, as long as
there is sufficient light to see
16. Why not?
qualitative, not quantitative
cannot be used to accurately
test the hardness of industrial
materials
17.
18.
19. Crystal Form/Habit
external shape of a crystal or groups
of crystals is displayed / observed as
these crystals grow in open spaces
reflects the supposedly internal structure
(of atoms and ions) of the crystal
(mineral)
the natural shape of the mineral before the
development of any cleavage or fracture
20.
21.
22.
23. Color and streak
a lot of minerals can exhibit same or similar
colors. Individual minerals can also display
a variety of colors resulting from impurities
and also from some geologic processes
like weathering
Streak is the mineral’s color in powdered
form. It is inherent in almost every mineral,
and is a more diagnostic property
compared to color.
26. Color different from streak
Source: http://www.instructables.com/id/How-toidentify- a-Mineral/step6/Streak/ (8/30/2015) Color vs streak of a
hematite (Fe2O3)
27. Cleavage
the property of some minerals to break
along specific planes of weakness to form
smooth, flat surfaces
these planes exist because the bonding
of atoms making up the mineral
happens to be weak in those areas
28.
29. Specific gravity
the ratio of the density of the
mineral and the density of water
this parameter indicates how many
times more the mineral weighs
compared to an equal amount of water
(SG 1)
31. magnetism, odor, taste, tenacity,
reaction to acid
magnetite is strongly magnetic
sulfur has a distinctive smell
halite is salty
calcite fizzes with acid as with dolomite but
in powdered form
32. magnetism, odor, taste, tenacity,
reaction to acid
magnetite is strongly magnetic
sulfur has a distinctive smell
halite is salty
calcite fizzes with acid as with dolomite but
in powdered form
35. Silicates – minerals containing the two
most abundant elements in the Earth’s
crust, namely, silicon and oxygen.
silicon oxygen tetrahedron –
fundamental building block of silicate
minerals.
Over 90% of rock-forming minerals
belong to this group.
41. Sulfates – minerals containing sulfur
and oxygen in the form of the (SO4)-
anion;
Sulfides - minerals containing sulfur
and a metal; some sulfides are
sources of economically important
metals such as copper, lead, and
48. 6. Native Elements – minerals that form as individual
elements
a. Metals and Intermetals – minerals with high thermal
and electrical conductivity, typically
with metallic luster, low hardness (gold, lead)
b. Semi-metals – minerals that are more fragile than
metals and have lower conductivity
(arsenic, bismuth)
c. Nonmetals – nonconductive (sulfur, diamond)
49.
50. 7. Halides – minerals
containing halogen
elements combined
with one or more
metals
Editor's Notes
Naturally- occurring - not man-made or machine generated; inorganic – not a by-product of living things; basic building blocks of rocks
The test is easy.
ii. The test can be done anywhere, anytime, as long as there is sufficient light to see scratches.
iii. The test is convenient for field geologists with scratch kits who want to make a rough
identification of minerals outside the lab.
The test is easy.
ii. The test can be done anywhere, anytime, as long as there is sufficient light to see scratches.
iii. The test is convenient for field geologists with scratch kits who want to make a rough
identification of minerals outside the lab.
Left picture: blocky/cubic or equant (it has equal growth rate in three
dimensions). Middle picture: bladed habit (it resembles a blade, with varied
growth rates in 3 dimensions). Right picture: needle-like habit (rapid growth of
crystals in one dimension while slow in other dimensions).
Color can be different from streak
Color can be different from streak
Color can be different from streak
Color can be different from streak
Color can be different from streak
When minerals break evenly in more than one direction, cleavage is described by the number of
cleavage directions, the angle(s) at which they meet, and the quality of cleavage (e.g. cleavage in
2 directions at 90°). When minerals break evenly in more than one direction, cleavage is described by the number of
cleavage directions, the angle(s) at which they meet, and the quality of cleavage (e.g. cleavage in
2 directions at 90°).
Cleavage is different from habit; the two are distinct, unrelated properties. Although both are
dictated by crystal structure, crystal habit forms as the mineral is growing, relying on how the
individual atoms in the crystal come together. Cleavage, meanwhile, is the weak plane that
developed after the crystal is formed.
Color can be different from streak
Color can be different from streak
Color can be different from streak
Color can be different from streak
Gypsum used in drywall and plaster of paris; barite used in paint, paper and textile- high gloss, silk varnish, acid resistant
