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Model: Chelsea Filter   


Chelsea Filter is designed to transmit only deep red and yellow - green light (best obtained under strong electric light). Just hold the filter close to your eye and look at the stones. Multiple stones can be viewed at once. It is helpful with identifying a few red gems and certain blue and green stones. Chelsea Filter can filter out mixed - in jewellery and differentiate emerald from emerald lookalikes. It is also useful for checking aquamarine and sapphires.


With the filter, emeralds usually appear distinctly red or pinkish in colour, while most imitations remain green. In rare cases certain emeralds, most notably from South Africa, may not show any pinkish colour at all. A synthetic emerald will react the same as a genuine one


Rubies (both genuine and synthetic) appear brilliant red under the filter. Synthetic blue spinel appear yellow - orange or pink while aquamarine and sapphires appear green or green - grey


This Chelsea colour filter has a glass filter. This gives better clarity, reduces distortion and provides better protection from humidity


The Chelsea Filter is a combination of two gelatine filters that transmit only deep red and yellow/green light. As Emeralds transmit light in the deep red spectrum but absorb light in the yellow/green spectrum, this combination is the most practical. It is a useful tool to distinguish natural emerald and natural green beryl, as well as most green and blue gems.


Whether you are a professional jeweller or a naturally curious amateur, use Chelsea identification filter to find out the true nature of gemstones!



* Accurately distinguish the real nature of the gemstones in an instant

* Supplied with leather pouch case

* Manufactured to strict quality and safety standards for long and trouble-free life

* Guaranteed high quality and accurate testing results


* Filter Diameter: 20mm
* Filter material: Glass
Body: Made of metal


How to use the Chelsea Filter

Just hold the Chelsea Filter close to your eye, place your green (or blue) gems under a strong electric light. There is no need to hold the filter close to a stone, even items in showcases can be examined providing they are lit by strong lights


The results are as follows

Type of Stone or Gemstone    Colour Shown through Filter or Apparent Color

Natural Emeralds                     Pinkish - Red
Synthetic Emeralds                  More intense Red
Emerald Simulants                   Green
Synthetic Green Spinel            Green
Peridot                                     Green
Green Sapphire>                     Green
Green Tourmaline                    Green
Chrome Green Tourmaline      Red or Pink
Demantoid Garnet andGreen Zircon      Red but with a negative reading

                                                                on the refractometer since no total

                                                               internal reflection occurs
Aquamarine, Blue Topaz and Zircon    Green
Lapis Lazuli                                          Weak Brownish Red
Cobalt Glass                                         Deep Red
Natural Blue Spinel                               Red
Synthetic Dark Blue Spinel                   Red
Natural Cobalt Blue Spinel                    Red
Synthetic Light Blue Spinel                   Pink - Orange
Blue Sapphire                                       Dark Green (almost Black)
Blue-Purple Color Change Sapphire    Usually appears Red
Most treated Jade                                 Reddish
Natural Jade                                         Green

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