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| How to Use a Polariscope |
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| A polariscope is used to differentiate between singly (isotropic) and doubly refractive (anisotropic) stones. A stone is placed between two polarizing filters and the top filter is then turned. If used with a conoscope, interference figures can also be seen with a polariscope. (Conoscopes are difficult to explain on paper, so directions for use are not covered here. We suggest you consult http://www.gemologyproject.com. They have videos showing the use of the conoscope. ) | ||
| 1 | Turn on | 1 Attach power cord and plug in the polariscope. On/off switch
at the back of the polariscope. |
| 2 | Place stone | Gently place stone on removable lense. Some people prefer to use tweezers to hold the stone between the two filters. We find this requires 3 hands, and simply rest the stone on the removable lense. |
| 3 | Rotating Lense | Turn on polariscope. Look through the upper lense of the polariscope. Rotate removable lense exactly 1 full rotation. Count the number of times the stone blinks (or goes from light to dark.) That count is the refractivity of the gemstone. |
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| 1 | Flashlight | Put the flashlight into the opening under the polariscope and tighten the screw to hold the flashlight secure. |
| 2 | Assemble | Insert this removable lense into the polariscope with narrow end down. Turn on flashlight. |
| 3 | Place Stone | Gently place stone on removable lense. Some people prefer to use tweezers to hold the stone between the two filters. We find this requires 3 hands, and simply rest the stone on the removable lense. |
| 4 | Rotating Lense | Look through the upper lense of the polariscope. Rotate removable lense exactly 1 full rotation. Count the number of times the stone blinks (or goes from light to dark.) That count is the refractivity of the gemstone. |
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| While looking through the top lense, and rotating the stone if the stone: |
| -stays dark throughout a 360° rotation= isotropic (single refractive). |
| -blinks 4 times,2 light and 2 dark during a 360° rotation = anisotropic (double refractive). |
| -stays light throughout a 360° rotation =microcrystalline or cryptocrystalline aggregate |
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-twinkles instead of blinks = anomalous double refraction (ADR) and is really isotropic ADR is when a stone looks like it might be blinking, but really is just showing lighter where the stone is thinner or where there is a veil or weakness in the stone. Garnet and diamond sometimes display this phenomena. |
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Isotropic |
Anisotropic Zircon |
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| Shows if a stone is doubly or singly refractive using precision glass lens instead of plastic. Sturdy metal housing with diffused lighting. AC-powered long lasting LED light source. Includes conoscope and holder.
This item is covered by our one year warranty! Item#: [29.409] Click for more info. |
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| The most popular guide to identifying gems and synthetics. Essential reading for collectors, dealers, and students to avoid mistakes and recognize opportunities. Authors: Antoinette Matlins and A.C. Bonanno Hardcover. 330 pages. Item#: [B0676] Click for more info. |
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