 |
 |
|
 |
||
 |
||
|
|
 |
|
|
|
|
|
||
|
||
|
|
|
|
 |
 |
|
|
|
 |
Refractometers, Dichroscopes, Polariscopes & Chelsea Filters
Refractometers are used to measure the refractive index of faceted gem stones, providing a quick reliable method to differentiate between diamonds and colored stones with their many imitations.
Back to
Optical Gateway
Measuring
Tools Gateway 
Gemological Gateway
|
|
Calcite Dichroscope-
Shows whether or not a stone is dichotic
(reflects 2 colors). Made with Calcite for long lasting
use. Protective leather carry case included.
Stock# 0502 Price $99.95 |
 |
Polariscope- Visually
shows if a stone is doubly or singularly refractive. Also used for
identifying Moisannite and detecting strain in diamonds. Precision
Japanese optics glass lens (not plastic). Battery operated.
Includes light source and batteries. Made in USA.
Stock# 0503 Price $259.95 |
|
|
Chelsea Filter- Helpful
in identifying certain red, blue and green stones. Used to determine
whether a stone is natural or synthetic. Can also be used for
detecting synthetic blue Spinel and detecting dyes in certain gems
Stock# 0506 Price $59.95 |
|
The Chelsea filter is a much used gemological dichromatic filter
that was originally devised by Anderson and Payne in 1934 at the Gem
testing Laboratory of the London Chamber of Commerce. The filter was
devised with the collaboration of gemology students of the Chelsea College
of Science and Technology. As this filter allowed transmission of both
deep red wavelengths around 690 nm and yellow-green wavelengths, around
570 nm, that matched emerald’s emission and absorption characteristics,
it was initially recommended to assist the discrimination between natural
emerald and its stimulants such as green glass, tourmaline, peridot etc.
This discrimination was possible because chromium -- containing iron --
and vanadium free emeralds emitted a red fluorescence when illuminated by
white light that had a content of ultraviolet wavelengths.
Synthetic emeralds were commercially introduced around 1940. These produced the same pink-red response as some emeralds through the Chelsea filter. However, although this filter was unable to predictably discriminate between natural and synthetic emerald, it was subsequently found capable of distinguishing aquamarine, blue topaz and their blue synthetic spinel stimulants, for unlike natural gemstones blue cobalt-containing synthetic spinels emitted a red fluorescence under white light. HOW TO USE A CHELSEA FILTER Hold the filter an inch or two from the eye. Light the stone with a strong light bulb or torch. The stone may appear to change color. The filter must be held near to the eye but there is no need to hold the filter close to the stone, even items in showcases can be examined providing they are lit by strong lights. |
|
 |
Shor GemPro Refractometer- The GemPro refractometers features an easy viewing lens and a superior hemicylinder for increased scratch resistance. Can test stones even when they are still mounted in the ring. Light source, refractive index liquid, monochromatic filter and carrying case are included. Lens is removable. Liquid has a refractive index 1.80, and a weight of 10 grams.
|
 |
PortaPac Mini Lab The PortaPac features the GemPro refractometers and the GemPro Polariscope. It also includes a Haneman Aqua color filter, mm gauge, 10X loupe, mini Maglite, gem cloth and tweezers. All fit into a plastic carrying case. Weight 3 lbs.
|
 |
Gem Kit The Gem Kit is a classy way to offer many of the tools need to measure, handle and examine gemstones. The contents are packaged in a kidskin leather pouch made for the purpose of holdering gemstones. The set includes Italian made tweezers with deep groove, brass millimeter guage with plate, 10x triplet with black nylon rope chain and Softshine brand lint free cleaning cloth.
|
|
|
|
|
 |
|
|
The I. Shor Co. |
|
I. Shor Canada |
| Shor International Corporation | |
| Fine Tools, Equipment and
Innovative Products Since 1918 20 Parkway West, Mt. Vernon, N.Y. 10552 Phone (914) 667-1100 Fax (914) 667-0190 |
|
|
e-mail: |
|
