This 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 jewelry and differentiate emerald from emerald look alikes. It is also useful for checking aquamarine and sapphires.
This Chelsea color filter has a glass filter. This gives better clarity, reduces distortion and provides better protection from humidity. It is also a combination of two gelatin 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.
Set includes :