Difference between revisions of "Polariscope"
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==Basic== | ==Basic== | ||
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A polariscope uses polarized light for gem identification. It consists of two polarized filters, one on the top and one on the bottom of the instrument as seen in the above picture. Both the polariser and the analyser have their own vibrational planes. When the vibrational plane of the polarizer is at right angles to the vibrational direction of the analyser, the field between them remains dark. This position is known as the "crossed position". In this position, gems can be tested to determine if they are:<br> | A polariscope uses polarized light for gem identification. It consists of two polarized filters, one on the top and one on the bottom of the instrument as seen in the above picture. Both the polariser and the analyser have their own vibrational planes. When the vibrational plane of the polarizer is at right angles to the vibrational direction of the analyser, the field between them remains dark. This position is known as the "crossed position". In this position, gems can be tested to determine if they are:<br> |
Revision as of 07:11, 2 July 2006
Basic
A polariscope uses polarized light for gem identification. It consists of two polarized filters, one on the top and one on the bottom of the instrument as seen in the above picture. Both the polariser and the analyser have their own vibrational planes. When the vibrational plane of the polarizer is at right angles to the vibrational direction of the analyser, the field between them remains dark. This position is known as the "crossed position". In this position, gems can be tested to determine if they are:
- Isotropic
- Anisotropic
- Anamolously Double Refractive or an
- Anisotropic Aggregate
The polarising filters in this instrument are made of a plastic with microscopically oriented crystals of quinine idosulphate.
Advanced
content needed
Conoscopy
Expert
content needed
Retardation
content needed
Elipsoids
content needed