1 / 16

Lecture 16 (11/20/2006) Analytical Mineralogy Part 3: Optical Properties of Biaxial Minerals

Lecture 16 (11/20/2006) Analytical Mineralogy Part 3: Optical Properties of Biaxial Minerals. Optical Indicatrices. A 3-d map of the indices of refraction for various vibration directions of light rays

lucian-richardson
Download Presentation

Lecture 16 (11/20/2006) Analytical Mineralogy Part 3: Optical Properties of Biaxial Minerals

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Lecture 16 (11/20/2006)Analytical MineralogyPart 3:Optical Properties of Biaxial Minerals

  2. Optical Indicatrices • A 3-d map of the indices of refraction for various vibration directions of light rays • Orientation of the indicatrix within a mineral is symmetrical with the crystallographic axis Anisotropic- Biaxial Orthorhombic Monoclinic Triclinic Anisotropic – Uniaxial Tetragonal Hexagonal Isotropic Isometric

  3. Biaxial Indicatrix Principal vibration axes greatest n lowest n intermediate n < ’<<’<

  4. Circular Sections and Optic Axes Circular Section Optic Plane Optic Axes Circular Section

  5. 2V and the Optic Sign Trace of Circular Sections - +

  6. Random Section through the Biaxial Indicatrix Vibration plane parallel to stage Double refraction rays

  7. Variable Birefringence within a Biaxial Mineral =0 =max

  8. Biaxial Optic Axis Figures Look for a mineral with the lowest interference colors, i.e. ~0

  9. Acute Bisectrix Figures (Bxa) Melatope (emergence of optic axes)

  10. Off-centered Bxa figure

  11. Determining the Optic Sign of Biaxial Minerals U D - + D U U D X D U + - U D X D U ’ is fast ray  is intermediate ’ is slow ray

  12. Estimating 2V by Curvature of Isogyre

  13. Estimating 2V by Separation of Isogyres

  14. Extinction Angle Parallel Inclined Symmetrical

  15. Sign of Elongation Slowing down the slow ray Interference colors increase Example – Length slow slow ray

  16. Next Lecture 11/22/06 Principles of X-ray Mineralogy Read: Klein p. 309-321

More Related