OPTICAL MINERALOGY AND PETROGRAPHY (POLARIZING MICROSCOPE) Flashcards
Concentrates Light
Collector lens system
CONTROLS light ray bundle at the source field
FIELD IRIS Diaphragm w/ring
Filter w/c approximates Daylight
Filter mount w/ blue filter
Polarizes light in one direction
Polarizer (Lower Polar)
controls and illuminates light coming from the source field directed to the object field or simply controls light focus
Condenser
Controls CONE OF LIGHT and its INTENSITY catering to the objective. Slightly closed for Becke Line test
Aperture Iris Diaphragm
The platform where samples or thin sections are being placed
Stage
Helps fix the specimen on stage so that it will not move while conducting observations
Stage Clips
Use for point location and systematic traverse in a species along mutually perpendicular directions
Mechanical Stage w/ Vernier Scale
Used to bring the specimen into sharp focus under LOW POWER and is used for all focusing when using high power
Fine Adjustment Knob
Used the move the stage up and down to decrease and increase working distance
Coarse Adjustment Knob
Holds the objective lenses
Revolving Nosepiece
Essential lenses of Microscope for magnification and Resolution enhancement
Objetive Lens (Objectives)
For insertion of microscopic accessory plate
Test plate
Located usually above the objective lens and used to polarize light perpendicular to the polarization of the lower polarizer
Analyzer (Upper Polarizer)
A small lens below the ocular used to view interference figure
Amici-Bertrand Lens
Essential lenses of micrisicope for magnification or resoltuon of images coming from the objectives
Eyepiece/s
Used to focus eye pieeces
Diopter Adjustment Ring
An accessory plate aka as one wavelength or first order red plate whch gives 1st order red interference color with crossed polar with its permitted electric vectors at 45 deg to those of the polarizer and analyzer and is used to dertermine fast and slow directions by increasing and decreasing retardation
Gypsum Plate (Lambda Plate) (550nm)
An accessory plate used to determine BIREFINGENCE and OPTIC SIGN that produce interfernce colors from the beginning of the First to the end of the Third or Fourth order. (0.009)
Quartz Wedge
Cut to such thickness that increases or decreases retardation of a section by about 1/4wavelength (Sodium light)
Mica Plate (1/4lambda plate)
Beam of Light consists of STREAM OF MINUTE PARTICLES or PHOTONS set at high velocity by a luminous body that travel thru space in STRAIGHT LINES
Corpuscular Theory
Considered light to be transmitted by VIBRATION of PARTICLES IN THE WAVES and may be used to readily explain reflection refraction, diffraction and interference
Wave Theory
Who is the proponent of Wave Theory
Christian Huygens
Porposed that light is made up of waves but not of vibrating particles but of EM which are fields normal to each other and normal to the direction and propagation of light
Electromagnetic Theory
Who is the proponent of the EM theory
James Maxwell
Assumes that light are quanta which is radiated discontinuously by a black body
Quantum Theory (Plank)
Observation of Realitistic virtual image with a flat field
Orthoscopic Observation
Observation that yields interference figure w/c represent an optical pattern caused by behaviour of light in individual crystals
Conoscopic Observation
Setup when light hitting the thin sectio is polarized to the NS vibration direction and light vibrates only in one direction
PPL
Steup when another polarized is inserted in the E-W vibration direction and crosses the earlier N-S polarized light
Cross Polarized Light (XPL)
Light is strongly converged to produce a interference figure
Conoscopic Observation
Set up for PPL
Bertrand Out
Analyzer Out
Condenser top lens out -
Polarizer In
Light Source On
Set up for XPL
PPL + Analyzer in
Set up for Conoscopic
PPL + Condenser Top Lens IN + Bertrand Lens
Centering the Stage with the Field
Centered when axis of rotation coincides with the tube axis, the tube axis standing perpendicular to the center of the field of view
How mant optic class is possible?
5
Dichroic Minerals
Uniaxial
Trichroic Mienrals
Biaxial
