Glowing minerals

Make powdered minerals glow in the dark!

15 minutes



  • Put on protective gloves and eyewear.
  • Conduct the experiment on the plastic tray.
  • Remove protective gloves before lighting the splint.
  • Keep flammable materials and hair away from the setup.
  • Do not attempt to extinguish the solid fuel with water – let it burn down completely.
General safety rules
  • Do not allow chemicals to come into contact with the eyes or mouth.
  • Keep young children, animals and those not wearing eye protection away from the experimental area.
  • Store this experimental set out of reach of children under 12 years of age.
  • Clean all equipment after use.
  • Make sure that all containers are fully closed and properly stored after use.
  • Ensure that all empty containers are disposed of properly.
  • Do not use any equipment which has not been supplied with the set or recommended in the instructions for use.
  • Do not replace foodstuffs in original container. Dispose of immediately.
General first aid information
  • In case of eye contact: Wash out eye with plenty of water, holding eye open if necessary. Seek immediate medical advice.
  • If swallowed: Wash out mouth with water, drink some fresh water. Do not induce vomiting. Seek immediate medical advice.
  • In case of inhalation: Remove person to fresh air.
  • In case of skin contact and burns: Wash affected area with plenty of water for at least 10 minutes.
  • In case of doubt, seek medical advice without delay. Take the chemical and its container with you.
  • In case of injury always seek medical advice.
Advice for supervising adults
  • The incorrect use of chemicals can cause injury and damage to health. Only carry out those experiments which are listed in the instructions.
  • This experimental set is for use only by children over 12 years.
  • Because children’s abilities vary so much, even within age groups, supervising adults should exercise discretion as to which experiments are suitable and safe for them. The instructions should enable supervisors to assess any experiment to establish its suitability for a particular child.
  • The supervising adult should discuss the warnings and safety information with the child or children before commencing the experiments. Particular attention should be paid to the safe handling of acids, alkalis and flammable liquids.
  • The area surrounding the experiment should be kept clear of any obstructions and away from the storage of food. It should be well lit and ventilated and close to a water supply. A solid table with a heat resistant top should be provided
  • Substances in non-reclosable packaging should be used up (completely) during the course of one experiment, i.e. after opening the package.

FAQ and troubleshooting

I accidentally mixed the marble and fluorite. What should I do?

Continue the experiment and observe the result. After the stove has cooled down, repeat the experiment without mixing the marble and fluorite. Compare your results.

How can I perform the last few steps of the experiment in the dark?

It’s a good idea to keep a light source near your workspace (for instance, a dim light or phone light). Turn it on and quickly light a wooden splint. Then set fire to the solid fuel and turn off the light. And, of course, you can ask an adult to switch the light off right after you ignite the solid fuel. Wait for the result!

I don’t see a glow. What should I do?

Note that the glow is pretty short-lived. Watch carefully after you ignite the solid fuel and turn off the light!

If you followed the instructions carefully and didn't mix the reagents, perhaps your room isn’t dark enough. Try conducting the last steps of this experiment in the evening with all the lights off and the windows shuttered, or in a room that can be made almost completely dark. Be careful in the darkness and don’t rush!

It’s also possible that there wasn’t enough solid fuel. Repeat the experiment with two big spoonfuls of solid fuel. Also, note that the minerals will only glow the first time they’re heated.

What should I do with the reagents after the experiment?

First of all, wait until the solid fuel burns down completely and the stove cools down. Dispose of all the compounds with ordinary household waste – they are perfectly safe for the environment.

How can I extinguish the solid fuel?

Don't extinguish the solid fuel yourself! Wait until it burns out. Unburned solid fuel emits an unpleasant odor, so it’s best to let it burn down completely. Be sure to wait for the stove to cool down. When the thermosticker on the stove is once again completely black, you can remove all the compounds and disassemble the stove.

The paper isn't glowing after exposure to the flashlight.

In this case, try holding the flashlight closer to the paper.

Can I use my own photos to test the light-sensitive paper?

Yes, of course! You just need to make sure that your screen is set to maximum brightness and the photo is reasonably contrasted.

Step-by-step instructions

You're going to need a lot of heat for this experiment. Solid fuel can provide just enough.


White marble CaCO3 and fluorite CaF2 powders look rather unassuming and, frankly, quite boring.


Not only do these powders look dull, they are quite inert, and don’t react with anything or with each other even when you heat them. But for some reason they start to glow. How come?



Please refer to local regulations when disposing of chemicals. Dispose of other solid waste with household garbage.

Scientific description

As it turns out, there's more to minerals than just their formulas. Take marble, which is mostly CaCO3. Its constituents, Ca2+  and CO32\- , are organized in an orderly "crystal lattice." Small amounts of radiation  always present in the environment are constantly hitting the compound, providing it with some energy.

The radiation doesn't make these minerals radioactive. Instead, some of their electrons receive enough energy to occupy so-called "excited" states . In marble and fluorite, these electrons can be trapped this way for long periods of time. If the mineral is heated, all the atoms in it start shaking and wiggling like crazy , and the electrons drop from their "excited" states, releasing some of their accumulated energy in the form of visible light .

In some substances, electrons can get "excited" enough to produce light simply via exposure to... light! And what’s more, some substances can gradually release this light even without being heated. If you hold such a substance under a lamp and then look at it in the dark, you'll see a nice glow. In fact, you have some at your disposal, applied to a sheet of paper. Try it! By the way, if you heat it a little (by placing a hot cup on it, for example), it will glow brighter for pretty much the same reason marble and fluorite glow.

That’s interesting!

How do glow sticks work?

Glow sticks glow due to the chemical reactions taking place inside them. The sticks consist of an outer vessel (the stick itself) and an inner vessel (normally a small plastic or glass capsule), which both contain reagents. When the inner vessel is broken (usually by bending the stick), the reagents mix and begin to react, and the stick begins to glow. The phenomenon we observe is called chemiluminescence.

The glow stick will emit light for the duration of the reaction. The reaction can be neither stopped nor reset. Chemical light sources are one-time-use only. There exists a common myth about “recharging" glow sticks by putting them in the freezer – in reality, this merely slows the reaction almost to a halt. Conversely, the higher the temperature, the more briefly, but more brightly, the stick will glow. These sticks are used in various events such as festivals, parties, and corporate events. They can also be used as emergency flares while hiking, hunting, fishing, or diving. Glow sticks are an indispensable resource in the absence of other light sources and in cases where standard light sources cannot be used (for example, in the event of a gas leak).

Glow sticks are almost completely non-toxic, but it still isn’t a good idea to break them open. Avoid bending glow sticks excessively or multiple times – they are durable, but not immortal.