-40%
Gem Table Top Polariscope with gem clip! *NEW* black
$ 51.74
- Description
- Size Guide
Description
Gemmologist tool for testing transparent gemstonesObservation of optical properties, glass strain, etc.
High
brightness
full spectrum light (400nm-700nm)
A CONOSCOPE is included.
Detachable European style crocodile clip included, you can rotate the stone in any direction. With conoscope, you can get the interference figure with ease ! (interference figure help to define the optic axis.)
You can use worldwide (110-240V 50/60Hz 10W).
Adaptable plug for your country (if not, we will provide free adapter).
Size 8cm(W) x 12cm(L) x14cm(H) , with a viewing field 40mm in diameter.
With a table glass(55mm in diameter) over the lower polarizer for place your gemstones.
Dual illumination
A refractometer light source window on the front of the polariscope(non-monochromatic light)
Latest model in good quality,made by metal and high quality optic glass.
New in excellent condition
The polariscope will tell you about a gemstone with ease. By simply holding the stone between the polaroid plates you can identify the stone as being double refractive (DR) or single
refractive (SR), and whether a gem material has internal strain that could cause damage to a stone easily.
Single Refractive Gemstones(SR):
will have no optic character. They are single refractive and will
offer you no optic character to see.
Double Refractive Gemstones(DR):
Will offer you a cross hair looking optical character, a bulls-eye, or a double arrow figure. To see these characters you will place your gemstone between the two polarizing filters as look for the optic
character using the Conoscope
.
If the gemstones is single refractive, no optic character will be seen. However, if the stone is double refractive, you should be able to find one of the following figures. But you may have to take some time and look at the stone from all directions to be able to find it. Which may make stones set in jewelry difficult to test. But if you look properly, and practice enough to become experienced in what you
are looking for, you will start finding the optic interference figure fairly easily
Determining the optic character of a gemstone is a very important test that can be done with the polariscope through actual observation of the optical interference figure. The refractometer can also identify this characteristic by taking the various readings and determining the stones optic character. However, it is easier and faster to do this with a polariscope, if you know what you are looking for. Gemstones will have three basic possibilities with the polariscope: Single Refractive, Double Refractive-Uniaxial, and Double Refractive-Biaxial. It is a matter of advanced study to fully understand the differences in these types, but being able to identify the optic character will greatly help you identify a stone.see the optic interference figure you should view the gem material between the polaroid plates and look for a rainbow effect showing through the stone. This will be different from strain colors which you will see as you get more experience. Once you see the rainbow effect ,use the conoscope, which is a small glass sphere on a handle, that will allow you to focus on the interference figure and be able to better see it...
Our client can get professional consultation and free technical support on gemmological product. (We are FGA holder and your question are welcomed.)
observations
conclusions
examples
Stone remaines dark through 360
° rotation in all orientations
Isotropic – amorphous or cubic
Garnet,spinel,paste,natural,
glass,fluorite,diamond,opal,
plastics
Stone becomes light and dark four times through each 360
° rotation in most orientations.
Anisotropic – uniaxial or biaxial.
Beryl,chrysoberyl,corundum,feldspar,
Peridot,quartz,topaz,tourmaline,zircon,
Tanzanite
Stone stays light through 360
°
Rotation in all orientations.
Polycrystalline.
Some twinned crystals.
Some doublets and triples.
Anomalous internal
Reflection effects.
Jadeite,nephrite,chalcedony&agate,
Twinned sapphire,
Sapphire&synthetic ruby, doublet
Reflection from cleavage in fluorite
Stone shows anomalous extinction effect.
Strain anisotropy , often in otherwise isotropic material.
Almandine garnet,diamond,paste,natural glass,verneuil synthetic spinel,
Some plastics,amber,some fire opal
A polariscope will tell you about a gemstone with ease. By simply holding the stone between the polaroid plates you can identify the stone as being double refractive (DR) or single refractive (SR), and whether a gem material has internal strain that could cause damage to a stone easily.
It will be mailed to you from Hong Kong directly, with packaging to avoid damage, thru' standard registered Air Mail.
We ship worldwide with one fixed shipping cost !
Now you can enjoy guarantee, if malfunction or broken within 1 year, you can return to us and replace a new one ! (except Mishandling.)