Rock-Forming Minerals: PHYSICAL Flashcards
Mineral
a NATURALLY occurring, INORGANIC, HOMOGENEOUS SOLID , with a DEFINITE chemical composition, and an ORDERED crystalline structure.
Some minerals are TOO SMALL to be identified by the naked eye that is why there is a need for high-powered instruments such as a petrographic microscope and X-ray diffractometers (XRDs).
TRUE
how many are the physical properties of minerals?
9
what are the physical properties of minerals?
hardness
streak
color
luster
cleavage
fraction
specific gravity
crystal habit
PP: colors
wavelengths of light that are reflected by the material
PP color is the most noticeable property
TRUE
PP: using colors as sole basis for mineral
identification is not enough because different minerals can have the same color.
TRUE
PP: color is highly affected by ??? (2)
impurities and light diffraction
PP: 3 classifications by color
- idiochromatic
- allochromatic
- pseudochromatic
PP: COLOR IDIOCHROMATIC
colors stay the same, CONSTANT
self-colored
malachite (always green), rhodochrosite (always red) and sulfur (always yellow)
PP: COLOR ALLOCHROMATIC
colorless in purity, kaya nagkakaroon ng purities
weakly-colored
amethyst and rose
PP: COLOR PSEUDOCHROMATIC
false-colored, colors are due to light diffraction
bornite
PP streak
color of the powdered form of a mineral.
PP color of the mineral is always the same with the streak color
FALSE. NOT ALWAYS
PP steak is more reliable than mineral color for identification becoz streak colors NEVER change.
TRUE
PP luster
appearance of a mineral’s surface and is dependent on how it reflects light.
PP what are the types of luster?
pearly
silky
dull
resinous
earthy
adamantine,
vitreous or glassy
metallic
PP: crystal habit
characteristic shape in which a mineral grows and is a
projection of the mineral’s crystal structure
PP: common crystal habits?
acicular
blocky
tabular
fibrous
bladed
dendritic
prismatic
PP: cleavage
tendency of some minerals to break along FLAT surfaces.
PP: cleavage has the WEAKEST atomic bonding which means that when you use a hammer to break a mineral, it will always break along these points.
TRUE
PP: cleavages are parallel and they occur repetitively
TRUE
PP: types of cleavages
basal
prismatic
non-prismatic
cubic
rhombohedral
octahedral
sphalerite
PP: Fractures
The pattern in which the mineral breaks aside from its planes of cleavage.
PP: fractures have atomic bonds with EQUAL STRENGTH
True
PP: Fractures do NOT break along planes; it just breaks UNEVENLY.
TRUE
PP: types of fractures
conchoidal
jagged
uneven
splintery
PP: hardness
resistance of the minerals to scratching. It is measured by
scratching the mineral with another object of known hardness.
PP: Mohs scale of hardness is used which is composed of ten minerals, numbered from 1 to 10 (1 as the softest and 10 as the hardest).
TRUE
PP TALC SOFTEST
DIAMOND HARDNESS
TRUE
PP: Specific Gravity
ratio of a minerals’ weight to the weight of an equal volume
of water
PP: a specific gravity of 4 means that a certain substance is four times heavier than water.
TRUE
The size of the mineral is DEPENDENT of its specific
gravity
FALSE! INDEPENDENT (a small mineral can have a big spec grav) doesn’t matter
