Bester dichroism observation gemstones pleochroism, pleochroism is to determine the basis of varieties of precious stones, especially when the refractometer, polarizer and other equipment can not determine whether colored gemstones are homogeneous or non-homogeneous body, usually a shaft Crystal gemstones may appear in two colors, known as the dichroism; two-axis crystal gems appear three colors, known as the three-color, collectively known as pleochroism.

Many bends of precious stones, in different directions can see a different color, this phenomenon is called multi-color.As the different gemstones of the multi-color strength and color is not the same color, so versatility is the identification of precious stones FID-1 type Icelandic stone dichroic mirror is the best instrument to recognize polychromaticity, and has good resolution for polychromaticity.As the gem color is the most obvious in the vertical optical axis direction, and the parallel light Axis direction is not significant multi-color, and therefore observed in the use of equipment from different directions, the specific operation should pay attention to the following points: prefix = o ns = 'urn: schemas-microsoft-com: office: office'

First, the operation steps

1 with the left hand thumb and index finger to take jewelry samples, the right hand to take the dichroic mirror, the dichroic mirror eyepiece close to the eyes, gem samples will have to close the window in the dichroic mirror, and close to the incandescent lamp, Of the daylight;

2 eyes through the eyepiece observation of two side by side the window, while rotating the sample, while constantly comparing the two windows presented by the color of the sample until the see pleochroism;

3 Stop rotating the sample and turn the dichroic mirror tube 180 °. If the colors of the two windows are interchanged, verify that the sample has pleochroism;

4 If you turn the sample 360 ​​degrees, do not see the multi-color, you should slightly turn the dichroic lens tube, and then turn the sample.If you still do not see the multi-color, you should put down the gem, with the original vertical direction Live, repeat the previous steps. If you still do not see the multi-color, then the gem is not versatile.

Second, observe the main points

1. Light source: Dichroic mirror requires the use of unpolarized white light as a light source. Suitable light sources are: daylight; incandescent and fluorescent lamps, etc. When using the fluorescent lamp, avoid using the light of the edge of the fluorescent lamp.

2. window: dichroic mirror window, the iceland stone prism after the formation of double shadow.Observation from the eyepiece, showing that two parallel windows.Jewelry samples in front of the window, the same will form a ghost.Thus in the observation of pleochroism , The color of the region corresponding to the two images should be compared.

3. Only the colored birefringence gems may have pleochroism, it is pleochroism of the gem must be birefringent.

4. Dichroism and trichromatic nature of the birefringence of the gemstones can also be divided into one-axis and two-axis crystal two-axis part of the two-axis crystal colored gemstones, there will be three-color, , Can only appear dichroism .Triaxis of the observation is difficult, not to dichroic intermediate excessive color as tri-color sex .To see the tricolor, is confirmed that the gemstones are biaxial crystal.

Third, the note

1. Iceland stone dichroic mirror optical instruments, to avoid vibration, moisture and overheating;

2. Keep the instrument clean and dry.

3. All parts of the instrument have been more positive, not free to disassemble.