Recognise false gemstones

A large number of gemstones, cut or rough, can be inspected simultaneously with irradiation by an UV lamp. Occasionally the UV behaviour of the stones under irradiation with the two different wavelengths is so characteristic that the UV lamp can also be used to directly determine stones. The use of the UV lamp is very effective in distinguishing between blue synthetic spinels and aquamarine or blue topaz. However, this procedure requires experience.

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Diamonds have a characteristic appearance under long-wave UV light. This becomes very clear when several stones of a piece of jewelery are viewed at the same time, as illustrated by the illustration of a necklace with colorless diamonds. Here a number of diamonds show no reaction to UV light; the majority of the stones shine in various light blue tones. Some stones can appear in yellowish or orange tones or, as here, shine in greenish tones.

Only the overall appearance of a complete piece of jewelry under UV light enables the stones to be clearly identified as diamonds. If different stones show irregular colors or shades, there is a high probability that the piece of jewelery consists of diamonds. If there were an appearance with uniform colors or shades of color, a piece of jewelry would probably consist of zirconia, moissanite or glass imitations or synthetic diamonds.

If you want to know exactly how UV light is used to identify gemstones and ornamental stones and would like to find out details about well-founded analysis methods, simply order our white paper “Luminescence examination”. This specialist publication was produced in collaboration with Prof. Dr. Jochen Schlueter wrote. He is a graduate mineralogist and responsible for the display collection of the Mineralogical Museum in Hamburg.

Do you want to read more?

Here you can order the whitepaper “Luminescence examination” free of charge, in which many analysis options are described. Simply enter your contact details here and we will send you our detailed white paper as a PDF on the subject of “Luminescence examination” by email.

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