Table polariscope

タイトルまたは説明

Polari scope is used to distinguish the homogeneous gem from nohomogenous gem and the crystalline aggregate, and test the abnormal birefringence of the gem. Under certain circumstance, use the conoscope to view the interference pattern and the uncoaxiality.

I，Technical parameter                         

1.polaroid:Diameter isï¿ *9mm

2.object stage：sample cell can rotate **0°  

3.Conoscope

4.electric power source：******0V，****0HZ；

5. Light source: Super bright LED

II，operation of Polari scope

  contra clockwise the base, take the insulation sheet away, then clockwise the base, plug the power source, LED are on now(**0°contraclockwise rotation，LED are off now);turn the analyses till the viewing field is full dark. Put the sample in the sample cell, view the reaction through the analyzer when make the sample cell **0°rotation

1. If it is always dark, means there is no light in the view field. Turn the gem, do the above again, if it is full dark again, the gem is honogeneous, that is unrefringence, the gem belong to isometrics system or amorphous jewelers.

2. If you see four times bright and four times dark, that’s full-dull, the gem is nonhonogeneous (uniaxial crystal or biaxial crystal) gem

3. The jade made from no homogeneous mineral is always bright when rotate the sample cell **0°.it is called total extinction

4. under optometric condition of polar light, appear irregular bright-dark strip or iridescence, and it remains the same when change the direction, so the gem is birefringence, it is called abnormal extinction.

III How to use the conoscope

Use the conoscope to view the interference pattern and the uncoaxiality.

1. Turn the analyzer till the viewing field is full dark that is the optometric position

2. Put the no homogenous gem on the object stage, put the conoscope 0.5cm above the sample, and rotate the object stage until you see the optical axial figure.

IV. Reaction of gem under Polari scope

Four bright and four 1.dark:crystal,moonstone,scapolite,Iolite,topaz,Peridot,Diopside,Apatite,Chrysoberyl,Corundum and the synthetic corundum, Zircon

2. Always bright: nephrite, jadeite, Chalcedony, Rhodochrosite, and colored Marble

3. Always full-dark: Glass imitation, Glass aerolite, Opal, Fluorite, Grossularite, Spinel, etc.

4. Abnormal extinction: part of glass imitation, part of opal, Fluorite, Grossularite, most part of Chocolate and Almandine, Synthetic spinel, most diamond, and some cubic zircon, etc.

IIV: Matters need attention

1. Crack of gem may interfere the effect of polariscope, so pls tell them apart

2. Put the gem with high refractive index into the oil with close refractive index, contour of the gem completely disappears and the inclusions are displayed.

3. This polar cope is not fit for Opaque and small gem.