Docstoc

OBSERVATIONS OF MINERAL optical

Document Sample
OBSERVATIONS OF MINERAL optical Powered By Docstoc
					                OBSERVATIONS OF MINERAL optical PARALLEL USING
                                ORTHOSKOP
                                   NIKOL




You can see pictures dargestellet as shown in Figure 4, viewed along the Z axis (with
positive optical mineral) or the X-axis (for optical mineral negative). (Grad <30) 2V lower
Austrittspünkte visible optical axis. Melatope is hot, as in the uniaxial. The Isogyren seen
again, and have the same meaning as in uniaxial minerals.
Optical properties of minerals can be observed in the position of Nikol Parallel:

1. Physical properties of minerals: color, relief, size and shape
minerals, corner parts, etc..
2. Relative refractive index.
3. Order double refraction (birefringence).
4. Axis interference.
5. Distribution and status of the optical axis of minerals.
6. Optical properties of the mineral-double refraction.
7. Extinction angle (dark / extinction).
8. Pleochroism minerals.




Thickness incision Vs. BF
• standard thin section thickness 0.03 mm; nature of interference
can only be observed in thin section 0.03 mm.
- Ct. Interference color of quartz bottommost: I order white
(gray) - Yellow order I.
• interference colors can be seen from the horizontal position
incision; diagonal lines are characteristic birefringence (BF).
• From the BF position, straighten down through the diagonal line
to the intersection: thick standard incision.
• Order the color interference and birefrience use
Michel-Levy color chart
                                          1. Relief


• Low: ir ∠ ≅ ∠
cb; ct: quartz,
orthoklas
• Medium: ∠ ir>
∠ cb; ct: plagioclase
• Height: ir ≥ ∠ ∠ cb;
ct: olivine, pyroxene




    2. Pleokroisme
                                          • That the nature of anisotropic mineral
                                          intrusions in absorbing light
                                          • Shown by beberapakali warnakristal change
                                          after playing
                                          up to 360o; position
                                          nikol parallel / cross.
                                          • Above: color
                                          biotite parallel interference
                                          C axis and pictures
                                          bottom: pleokroismenya
                                          on the corner of lap 90.


3. Type of Minerals Properties berdasrkan Pleokroiknya


• Minerals uniaxial (dichroic): two different warnayang parallel beam due to vibrations of
the vertical axis (c) and the axis of the base (b).
• Minerals biaxial: trichroic, 3 color changes associated with the three major axes (a, b, c).
• Ct: horenblende pleokrois strong and non-pyroxene pleokrois
4. Crystalline Form


• The crystal is determined by the orientation of its edges
• The irregular crystals on all sides called anhedral
• If most of the irregular crystals called subhedral
• If all the so-called irregular euhedral crystals




                                        5. cleavage

                                        More easily observed in a position parallel nikol but
                                        some minerals can also be observed in the position
                                        nikol cross.
                                        - No parts: quartz and olivine
                                        - Parts 1 direction is clear: the mica
                                        - 2 way around the obvious: pyroxene and
                                        amphiboles
                                        • Examples of minerals with cleavage angle both
                                        directions intersect to form an angle of 90 ° pyroxene
                                        • Examples of parts of the mineral with 2-way angle
                                        formed by the intersection angle of 60 ° / 120 °:
                                        amphiboles / horenblende

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:8
posted:10/6/2012
language:
pages:4