How to Use a Polariscope to Make Jewelry

A polariscope is used to determine the optic character of a gemstone. It is one of the most important tools in gemology. A polariscope with some modifications also can identify the optic sign of a gemstone and may allow additional internal features to be identified. The following steps will show how to use a polariscope with gems used in making jewelry.

Instructions

1

Set up the polariscope. Insert the flashlight into the opening below the unit and tighten the screw to hold it in place securely.

2

Insert the rotating lens into the polariscope with the narrow end facing down. Place the gemstone into the holder in the open space and turn on the flashlight.

3

Look through the viewer and turn the rotating lens one full rotation. Determine the refractivity of the gemstone by counting the number of times the gemstone goes dark during this rotation.

4

Repeat Step 2 several times to verify the count. A stone with single refraction can easily appear to be double refractive when its color is outside the refractometer's limit. This can occur with red stones such as garnet, spinels and rubies.

5

Analyze the results of the polariscope. A stone that is dark throughout the rotation is single refractive and a stone that is always light is a crystalline aggregate. The stone is double refractive if it blinks on and off four times over the rotation.

6

Convert a gemological microscope into a polarizing microscope. Place one polarizing sheet over the light source and another one below the optics at a 90-degree rotation from the first one. This may allow negative inclusions to be distinguished from solid inclusions.