{"id":6113,"date":"2024-02-13T07:48:18","date_gmt":"2024-02-13T05:48:18","guid":{"rendered":"https:\/\/efirgems.com\/fluorescence-and-phosphorescence-in-gemstones\/"},"modified":"2025-03-11T12:43:40","modified_gmt":"2025-03-11T12:43:40","slug":"fluorescence-and-phosphorescence-in-gemstones","status":"publish","type":"post","link":"https:\/\/efirgems.com\/en\/fluorescence-and-phosphorescence-in-gemstones\/","title":{"rendered":"Fluorescence and phosphorescence in gemstones"},"content":{"rendered":"\t\t
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In this article, we will introduce you to the common terms in gemology - fluorescence and phosphorescence. They can be very useful tools for gem testing and identification when used correctly.<\/p>

The word fluorescence was officially introduced in 1852 by Sir George Stokes. It is named after the stone fluorite, which is a highly fluorescent material.<\/p>

Fluorescence and Phosphorescence<\/strong><\/h4>

Fluorescence is the visible light that some gemstones emit when exposed to invisible ultraviolet (UV) rays. The visible light emitted stops when the source of UV rays is stopped.<\/p>

On the other hand, if the visible light emitted by the gemstone continues after the original source of UV rays is stopped then the gemstone phosphoresces.<\/p>

Fluorescence is a common method of testing and identifying gemstones. If we know the characteristics of different stones then the presence, strength and colour of fluorescence can give us clues as to the variety of stone we are testing. Another advantage is that we can test several stones at the same time as well as gemstones that are already mounted on a jewel.<\/p>

In gemology, gemstones are tested for the presence of fluorescence with two types of ultraviolet rays. The shortwave ultraviolet light (SW UV) that stimulates fluorescence in some stones typically has a wavelength of 254nm. On the other hand, long-wave ultraviolet light (LW UV) has a wavelength in the range of 320-400nm with its peak at 365nm.<\/p>

Both fluorescence and phosphorescence can have different strengths, which can vary from stone to stone from very strong to weak. If a gemstone does not fluoresce or phosphoresce, it is considered inert. The strength of fluorescence and phosphorescence may also vary depending on whether the stone is irradiated with SW UV light or LW UV light.<\/p>

Using UV Light to Test Gems<\/strong><\/h4>

For fluorescence and phosphorescence testing, a quality source of SW and LW UV light is required. Typically, a UV lamp is used for this type of testing and can illuminate the stone with either type of light. Such lamps are common in gemological shops and exhibitions and can usually be found for around 250-450 euros.<\/p>

When assessing the fluorescence and phosphorescence of a gemstone it is best to place it on a black surface. The test is best carried out in a completely dark room. Allow your eyes to adjust to the darkness and be sure to wear protective eyewear.<\/p>

A relatively high percentage of natural and synthetic diamonds can be identified from each other using this type of testing. This is due to the fact that colorless natural diamonds are mainly Type Ia and synthetic colorless diamonds are mainly Type IIa. While one emits a stronger light when illuminated with LW UV light compared to SW UV in the other it is the other way around. The fluorescence color is also usually different in natural and synthetic diamonds. We have dedicated a separate article on our blog to this topic in case you are interested in learning a little more about the different types of diamonds, their characteristics and the fluorescence and phosphorescence found in them.<\/p>

Although fluorescence can give us the indication we need about the type of gemstone, we should never rely on one test alone when trying to tell one stone from another.<\/p>

To be absolutely sure, it is necessary to go to a certified laboratory that has the necessary equipment.<\/p>

Summary<\/strong><\/h4>

In this article, we have introduced you to what fluorescence and phosphorescence are in gemstones. They can be very useful tools for testing and identifying gemstones when used properly.<\/p>

We have also prepared articles on our blog about the quality of diamonds<\/a>, what to know when choosing emerald<\/a>, sapphire<\/a>, ruby<\/a>, pearls<\/a> or opals<\/a>. We hope these make it even easier for you to choose the right stone. Of course, our gemologist consultant is always available for consultation.<\/p>

Efir offers both jewellery from its own collections<\/a> and making gold jewellery with diamonds and other precious stones according to the customer's design<\/a>. We work only with natural stones and precious metals.<\/p>

We can be contacted via contact form<\/a>, Facebook, Instagram or our phone number (+359) 898 241940.<\/p>\n<\/div>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"

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