What Are Fluorescent Minerals? Discover Gemstones under Ultraviolet (UV) Light!

Among gemstone and minerals collectors it's well-known that some minerals are fluorescent. These fluorescent minerals give off visible light under an ultraviolet lamp. Under normal light you won't see this but under UV light you'll see bright colors.

Collectors and museums usually have a special display case for this type of minerals. These are displayed on a darkened surface and background (commonly black) and when the UV light is turned on their fluorescent effect is visible. Some collectors specialize in collecting this type of minerals.

This article explains the basics of fluorescent minerals: what are they and why do they fluorescence under ultraviolet light?

Example of a fluorescent mineral

Here's an example of a mineral under normal light and under ultraviolet light:

A piece of calcite under normal light.
A piece of calcite under normal light. | Source
Source

In this case the mineral also looks nice under normal light but there are also fluorescent minerals which just look like an ordinary rock. You wouldn't notice that the rock is covered with fluorescent material unless you examined it under an ultraviolet lamp. These ultraviolet lamps can be purchases from mineral collecting stores, at local or international mineral events and you can also buy an ultraviolet lamp online.

Fluorescent Rhodochrosite
Fluorescent Rhodochrosite | Source

Books about fluorescent minerals

Ultraviolet light

We can distinguish between short-wave, medium-wave and long-wave ultraviolet light. This is the wavelength of the light that is being emitted by the ultraviolet lamp. This can influence whether or not the minerals will appear fluorescent.

  • Short-wave ultraviolet light has a wavelength of 100 nm - 280 nm.
  • Medium-wave ultraviolet light has a wavelength of 280 nm - 315 nm.
  • Long-wave ultraviolet light has a wavelength of 315 nm - 400 nm. This is also known as black light.

Some minerals are only fluorescent under one type of ultraviolet light but not under other types. It can also happen that the emit a particular color of light under one and a different color under another type of ultraviolet light.

Fluorescence under ultraviolet light is a physical phenomena which occurs in nature, such as gems and minerals, but it is now also used for other purposes, such as security features of bank notes. White clothing can also be fluorescent - this effect is sometimes used to entertain the crowd in nightlife venues.

When ultraviolet light hits fluorescent material, a reaction occurs which emits visible light. That's how you can see bright colors under ultraviolet light that are not visible under normal light. The fluorescent minerals can also emit light when viewed using X-rays and electron beams.

Chrysoberyl / Alexandrite
Chrysoberyl / Alexandrite | Source

How do I know if a mineral is fluorescent?

There are two obvious ways of checking. If you don't know the mineral name but you do have a UV lamp nearby you can check. Did you know that ultraviolet light is also used to find minerals in dark caves and mines?

Otherwise, you'll have to look it up in mineral books. These books often list this under properties of the mineral or otherwise in a separate list of fluorescent minerals. Here is a list of fluorescent minerals.

Some examples of fluorescent minerals are adamite, fluorite and scapolite.

Where can I buy an ultraviolet lamp?

As I said earlier, one of the places you can buy an ultraviolet lamp is online.

Where can I learn more about collecting minerals?

Have a look at my other articles about collecting gemstones and minerals:

This article was written by Simeon Visser. I am earning money online by writing here at HubPages.com. Would you like to earn money online as well? Read the success stories and sign up today to get started!

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Comments 2 comments

glowingrocks profile image

glowingrocks 5 years ago from New York

Nice hub.Love those pictures.


simeonvisser profile image

simeonvisser 5 years ago Author

@glowingrocks: Thanks. Pictures really help when explaining this subject :)

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