Product name: gemstone dichromatic mirror
Technical parameters:
* High quality Iceland SPAR, standard rectangular window
* Rotating bracket, gem and dichromatic mirror can rotate 360°
* Large eyepiece, clear observation effect
Main uses:
1. Helps identify gemstones with strong polychromatism such as cordierite with significant trichromatic (blue, purplish blue, light yellow)
2. Distinguish between isotropic and anisotropic gems such as rubies and red spinels
Ruby and red spinel are very similar in appearance and can be effectively distinguished by polychromatic observation.
Ruby dichroism is obvious; Spinel isotropic, no polychromatism.
3. Direct processing: understanding the polychromatism of gemstones is very helpful in cutting and sharpening gemstones. For example, in the processing of rubies, the top facet should be perpendicular to the optical axis, so that the best color of the gem can be displayed through the top facet.
Operation steps and precautions:
1. The light source should be white or natural light, and never monochromatic or polarized light.
2. The sample to be tested must be colored, transparent, with a birefringent gem.
3. The sample to be tested should be observed as close as possible to the dichromatic lens window with the eyes close to the eyepiece.
4. Rotating the gemstone and dichromatic mirror while observing, equiaxed crystal, amorphous gem and achromatic anisotropic gemstone do not show polychromatism, colored anisotropic gemstone does not show polychromatism in the direction of vertical optical axis.
5. If two colors appear in the dichromatic mirror window, the sample is a birefringent gem (anisotropy). If trichromatic, the sample is a biaxial gem.
6. The absence of polychromatism does not determine that the gem is isotropic.
7. When the two vibration directions of the gemstone and the two vibration directions of the Iceland SPAR prism are at an Angle of 45°, the polychromatism is not obvious.
8. The intensity of polychromatism is independent of the birefringence index.
9. Do not place gemstones directly on the light source. Some gemstones may change their polychromatism when exposed to heat.
10. Weakly polychromatic phenomena should be treated with suspicion, and if the test results are not certain, this test should be ignored.
