5 Polarization and Conoscopy |
5.6 Conoscopy Examinations
38
Primotech | Document 430055-9044-008 V.1.0; 03 / 2014
5.6 Conoscopy Examinations
In conoscopy examinations, the sample is illuminated by a wide cone of light. This
means that individual beams within the cone travel through the sample at different
angles.
In certain types of sample, these beams interact with each other to create an
interference pattern. This interference pattern can be used to infer properties of the
sample. Conoscopy refers to the examination of interference patterns caused by
such samples.
Conoscopy can only be performed with Primotech D/POL Conoscopy as it contains
a Bertrand lens which can be inserted into the beam path. The Bertrand lens causes
the interference patterns to be in focus when looking through the eyepieces rather
than the sample itself.
5.7 Performing Conoscopy Examinations
INFO
Conoscopy can only be performed with transmitted light.
Prerequisites
¢
You are using Primotech D/POL Conoscopy
¢
The sample is illuminated by transmitted light only
¢
The objective has an aperture > 0.6 (e.g. the 40x or 63x objective)
¢
The objectives are centered (see Centering the Objectives [
33])
Procedure
1
Select the objective with the largest magnification.
A minimum of 40x should be used. The 63x objective is recommended for
conoscopy examinations.
2
Focus the sample and move it so that only one mineral grain is in the field of
view.
This ensures the interference patterns are based only on a single grain.
