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Your cart is empty.This gemological tool is helpful for identifying certain red, blue and green gemstones. It is used to determine whether a gemstone is natural or synthetic and can also be used for detecting synthetic blue spinel as well as for detecting dyes in certain gemstones. The Chelsea filter is a popular 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 an emerald's emission and absorption characteristics, it was initially recommended to assist the discrimination between natural Emerald and its simulants 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. Espresso color and white color available. Please leave a message at checkout for color preference, otherwise we will send the black color as default color.
S. E.
2025-08-05 18:38:40
This is the first Chelsea filter I've owned so I don't have anything to really compare it to. Overall, I really like this and have been using it to test some gems in my collection. The only thing that is frustrating for me personally is that if you try to look through it in the same way you would a loupe it is very blurry. I have to hold it at a distance (about 4 to 6 inches away from my eye) to see the gem clearly, but then I wonder if I am seeing the color of the gem through the lens properly since it is relatively far away. But like I said, this is the first one I've owned so I'm not sure if they are all blurry up close. Still happy I got it and am having fun using it!
Tsuriel
2025-06-19 15:38:42
A very high quality product. Made of steel. Arrived quickly and intact. A must have product.
Dan King
2025-06-05 11:28:44
If you know how to use it. I is a great tool to have in your tool box. Caution! If you do not know how to use it, do not buy it. It will get you into more trouble than it is worth.
LS
2025-05-13 10:01:02
I love this little filter. I love knowing that I will never buy fake blue lapis again! If you go online you can find a chart that will help you to identify if the gem is real or not. YOU ALSO HAVE TO HAVE A REALLY GOOD LIGHT SOURCE IN ORDER TO SEE THE COLOR DIFFERENCES. Once you get that light source it's obvious if the gem is real or not. Very good product.
Qingjiang Zhu
2025-03-28 11:00:53
Easy to brings and need more using cost
MarÃa Luisa orozco MartÃnez
2025-03-10 15:28:21
Si sabes utilizarlos, es funcional
DragonHA
2025-01-28 16:46:20
This product is exactly what is described. Used to see if the specimen/gem is coloured with chromium. Can be used to identify genuine natural vs synthetic (or simulant) gems, such as emeralds and rubies. Happy with this purchase.
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