All about fluorite
Fluorite is a colourful mineral that is popular with collectors. It can be beautiful, but because of its low hardness it is less easy to polish in a rock tumbler than, for example, agate, jasper or quartz.
Fluorite, also known as fluorite stone or fluorspar, consists of calcium fluoride. The mineral occurs in various colours, such as purple, green, blue, yellow, white and colourless varieties. It is precisely this colour variation that makes fluorite popular as a collector’s stone and decorative stone.
What is fluorite?
Fluorite is a crystalline mineral with a hardness of about 4 on the Mohs scale. That makes fluorite clearly softer than many classic tumbler stones. By comparison: agate, jasper and quartz are around hardness 7. That difference is important if you want to work, store or perhaps gently tumble fluorite.
Fluorite often forms in hydrothermal veins and can occur alongside minerals such as quartz, calcite, barite and sulphides. The crystals can be cubic and sometimes have a glass-like lustre. Some pieces show multiple colour zones in a single stone.
Hardness
Fluorite has a hardness of about 4. As a result, it scratches and gets damaged faster than many harder stones.
Colours
Fluorite can be purple, green, blue, yellow, white, colourless or multicoloured. Purple and green fluorite are especially well known.
Is fluorite suitable for a rock tumbler?
Fluorite can sometimes be tumbled carefully, but it is not an easy stone for beginners. With a hardness of about 4, fluorite is soft and fragile. It can scratch, split, dull or damage more quickly than harder stones such as agate and jasper.
If you still want to use fluorite in a polishing tumbler, do not mix it with hard stones. Preferably use only fluorite or stones with a similar softness. Work carefully, check regularly and do not expect the same result as with hard tumbler stones.
- Not ideal for beginners: fluorite is softer and more fragile than classic tumbler stones.
- Do not mix with agate or quartz: harder stones can damage fluorite.
- Choose compact pieces: pieces with lots of fracture surfaces or crystal edges are riskier.
- Check more often: fluorite can wear down or get damaged faster.
- Be careful with grit: grit that is too coarse or tumbling for too long can remove too much material.
Important: for a first rock tumbler batch, agate, jasper or quartz are usually safer and more predictable than fluorite. Fluorite is especially interesting as a collector’s stone or for anyone with some experience.
Polishing fluorite: what should you pay attention to?
Fluorite calls for more caution than harder stone types. The stone has clear cleavage directions and can therefore break or damage more easily. Edges and points can also wear down quickly during tumbling. A standard schedule for hard stones is therefore not always suitable for fluorite.
| Property | What does this mean? | For the rock tumbler |
|---|---|---|
| Hardness 4 | Fluorite is relatively soft. | Do not mix with much harder stones. |
| Crystalline structure | Some pieces have clear fracture surfaces. | Susceptible to splitting or chipping. |
| Beautiful colour zones | Fluorite can be purple, green, blue or multicoloured. | Colour remains interesting, but the polishing result can vary. |
| Glass-like lustre | Well-shaped pieces can shine attractively. | Polish carefully and do not start too aggressively. |
Practical: if you mainly want to start with easier tumbler stones? Then check the category rough stones for rock tumblers.
Different colours and names of fluorite
Fluorite is often described by colour or appearance. In shops and collections you may see, for example, purple fluorite, green fluorite, rainbow fluorite, blue fluorite and yellow fluorite. The name usually says something about the colour, but not automatically about the quality or suitability for a polishing tumbler.
Purple fluorite
A well-known variety with violet to purple shades. Widely sold as a collector’s stone and decorative stone.
Green fluorite
Green fluorite can range from light green to deeper green. Sometimes green occurs together with purple or white zones.
Rainbow fluorite
A commercial name for fluorite with multiple colour bands or colour zones in one piece.
Fluorspar
The older or technical Dutch name for fluorite. You will mainly encounter this name in mineralogy and industry.
What is fluorite used for?
Fluorite is not only a collector’s stone. The mineral also has industrial applications, including as a raw material for fluorine compounds and in processes involving metal, glass and chemistry. In the minerals world, fluorite is especially prized for its colour, crystal forms and sometimes its fluorescent effect under ultraviolet light.
Fluorite is also often mentioned in spiritual and holistic contexts. Such meanings are mainly based on tradition and personal belief. For a rock tumbler, the physical properties are what matter most: fluorite is beautiful, but softer and more fragile than many beginner stones.
Polishing fluorite or other stones?
Fluorite calls for caution. If you are just starting to polish stones, harder and more compact stones are often easier. In any case, make sure you have a suitable polishing tumbler, the right grit and a clear step-by-step plan.
Can you find fluorite in the Netherlands?
Fluorite can occur at various localities in Europe, but in the Netherlands it is not an everyday find for hobby collectors. Minerals are sometimes found in rocks, gravel or old geological contexts, but beautiful fluorite crystals are not something you can just count on.
If you want to search for stones yourself, also read the page which stones can you find in the Netherlands and Belgium. For a predictable rock tumbler batch, it is usually more practical to buy suitable rough stones.
Buy fluorite or keep it as a collector’s stone?
Because fluorite is relatively soft, it is often wiser to keep beautiful crystals or striking pieces as collector’s stones rather than simply put them in the polishing tumbler. In particular, pieces with beautiful crystal forms, colour zones or fragile edges can become less attractive through tumbling.
As a collector’s stone
Beautiful crystals, cubic forms and colour bands often look better as a specimen than in the tumbler.
For the rock tumbler
Only compact, less fragile pieces are possibly suitable. Do not mix them with much harder stones.
Frequently asked questions about fluorite
Is fluorite suitable for a rock tumbler?
Fluorite can sometimes be tumbled carefully, but it is not an easy beginner’s stone. With a hardness of about 4, fluorite is softer and more fragile than agate, jasper or quartz.
Why is fluorite harder to polish?
Fluorite is relatively soft and may have clear cleavage directions. As a result, the stone can scratch, chip or break more quickly during tumbling.
Can you mix fluorite with agate or quartz?
That is usually not advisable. Agate and quartz are much harder than fluorite and can damage fluorite during tumbling.
What colours does fluorite come in?
Fluorite occurs in, among other colours, purple, green, blue, yellow, white, colourless and multicoloured varieties. Rainbow fluorite is a well-known commercial name for multicoloured fluorite.
Can fluorite fluoresce?
Yes, some fluorite can fluoresce under ultraviolet light. Not every piece of fluorite reacts equally strongly, but the effect is one of the reasons fluorite is popular with collectors.