optical mineralogy Flashcards
source of light
light source
polarizes light in one direction
polarizer
controls and illuminate light coing from the sourece
-it focuses the light in one area
condenser
controls the cone of light catering in the objective
-for relief ng minerals mo`
iris diaphragm
platform of the specimen
stage
fix the specimen on the stage
stage clips
used for centering the mineral on the stage, also used for point locations and systematic traverse of the specimen under the microscope
mechanical stage
it makes the stage go up or down
coarse adjustment knob
used for focusing image
fine adjustment knob
it holds the objectives
revolving nose piece
essential lenses of the mircoscope for magnification and resolution
objectives initial
4x, 10x, 20x, 40x
insertion slot for accessory plates
test plate
upper polarizer
analyzer
accesory plate used for observing interference figures
betrand lense
it increases retardation of a secion by about 4y
mica plate
used to determine fast and slow directions of light
gypsum plate
used to produce interference color beginning first to the end of the 3rd and 4th order
quartz wedge
light consist of particles or photons
corpuscular theory
light is transmitted by the vibration of particle in a wave
wave theory
christian huygens
considered light as waves that are electromagnetic
eletromagnetic theory
radiating oscillators in a black body radiate energy discontinuously in units called quanta
quantum theory
a perpendicular drawn to the surface of a wave front at any point of propagation of light
wave normal
locus of all the points of a medium of light
pinagsama samang wave normal
wave front
the direction which light is propagated
ray of light
perpendicular to the wave front
wave normal and the direction of propagation of the light rays are perpendicular to wave front
isotropic
light rays are not parallel to the wave nrmal
anisotropic
a curve combining movement around a circle with motion along a straight line
displacement
lies in the wave front and is perpendicular to the ray in isotropic media.
-in anisotropic media it is perpendicular only in limited directions
vibration direction
distance between two successive crests or troughs
wavelength
number of vibrations in a given unit of time
frequency
maximum displacement of a wave from the line of transmission
amplituted
the interval necessary for a wave to undergo a complete osccilation
period
the upper tip of the wave
crest
lower tip of the wave
trough
a group of light waves following along a sample path
beam
straight line path followed by light in moving from one point to another
ray
ration of the wave normal velocity in a vacuum to wave normal velocity in medium
refractive index
light of a single wavelength
monochromatic light
lies parallels to the plane of the wavefront
light vector
isotropic - perpendicular to the direction of the propagation
anisotropic - parallels, but not perpendicular to the direction of propagation
types of vector
electric and magnetic
speed of light
186,284 miles per second
299,792 km per second
combination of all the different wavelengths visible to the eye
wgite light
realistic virtual image with a flat field
orthoscopic observation
size of the sample
1 x 2 inches
you grind the sample in a ????
240 - 800 mesh abrasive
in cutting a sample you use a
diamond saw cutter
thickness of a sample in a thin section
0.03 mm
clean the thin section with a ?
xylol solution
pandikit ng sample mo sa glass slide
canada balsam
study of the interaction of light with minerals
optical mineralogy
study of opaque minerals using reflected light
ore microscopy
general application of optical mineralogy
identification of minerals
observed with prolonged light
color
change in color of a mineral in varying degrees as the stage is rotated due to differences in light absroption
pleochroism
the ability of a mineral to separate into smaller particles bounded of faces of possible crystal form
cleavage
best explained in the terms of direction
straight line sa wave kung saan nagsisimula ang sukat ng crest or trough
inflection line
cleavage of pyroxene
87-93
cleavage of amphiboles
124-56
grains that show no recognisable crystal form
anhedral
grains that show imperfect but recognisable crystal form
subhedral
grains that show sharp and clear crystal form
euhedral
degree of visibility of a transparent mineral in an imersion medium
- the contrast between a mineral and its surroundings due to diference in RI
relief
R.I. of canada balsam
1.53
IR of the mineral is higher than the medium
high relief
RI of the mineral is lower than the medium
low relief
RI of the mineral and the medium is almost the same
zero relief
band or rim of light visible along a grain/crystal boundary in a plane polarized light.
central illumination method or becke line method
produced because of light spli into two rays on passing trough a mineral
interference color
michel-levy chart
the difference of n of the fast and slow ray
birefrringence
formation of rational symmetry intergrowth of two or more grains of crystalline specie
twinning
form of penetration twinning where two crystals form as penetration twins
carlsbad twinning
-may hati sa half
where to adjoining slabs or lamellae are mutually reversed with respect to each other and every alternate twin or slab has an indetical atomic structure
lamellar twinning
- stripes
- plagioclase
shows two kinds of repeated twinning i thin section, with one set of twins arrange at 90 degrees to the other set
cross-hatched twinning
or tartan twinning
-microcline
solid solution which do not have uniform solution
zoning
center of the mineral is more sodic becoming calcic towards the margin
normal zoning
center is more calcic becoming more sodic towards the margin
reverse zoning
steplike progression for more calcic interior to more sodic margins w/ local reversals in adjacent zones
oscillatory zoning
when mineral become dark parallel to the crosshairs
parallel extinction
mineral becoe dark at an angle
inclined/oblique extinction
planes to the diagonal; vibration direction is diagonal
symmetrical extinction
the arms of the uniaxial interrference figure forming a cross
isogyres
interference colors, band of colors in the uniaxial interference figure
isochromes
the point where the isogyres cross
melatope
the identification or interpretation of framework mineralogy and textures leading to classification of wallrock as sedimentary, metamorphic, or igeous
petrography