Pyrolusite facts for kids
Quick facts for kids Pyrolusite |
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| General | |
| Category | Oxide minerals |
| Formula (repeating unit) |
MnO2 |
| Strunz classification | 4.DB.05 |
| Crystal symmetry | P42/mnm |
| Identification | |
| Color | Darkish, black to lighter grey, sometimes bluish |
| Crystal habit | Granular to massive: botryoidal. Crystals rare |
| Crystal system | Tetragonal |
| Twinning | {031}, {032} may be polysynthetic |
| Cleavage | Perfect on 110 |
| Fracture | Brittle |
| Mohs scale hardness | 6–6.5, 2 when massive |
| Luster | Metallic, dull to earthy |
| Streak | Black to bluish-black |
| Specific gravity | 4.4–5.06 |
| Refractive index | Opaque |
| Major varieties | |
| Polianite | pseudomorphic after manganite |
Pyrolusite is a common mineral. It is mostly made of manganese dioxide, which is a mix of manganese and oxygen. This mineral is very important because it is a main source of manganese metal.
Pyrolusite usually looks black and does not have a clear crystal shape. It often forms in grainy, stringy, or column-like patterns. Sometimes, it can form kidney-shaped crusts. The mineral has a shiny, metallic look. It leaves a black or bluish-black mark, and it can easily make your fingers dirty. Its weight is about 4.8 times heavier than water.
The name Pyrolusite comes from two Greek words: pyro meaning fire and lousis meaning to wash. This name refers to how it was used in the past to remove unwanted colors from glass by heating it.
Contents
Where Pyrolusite Is Found
Pyrolusite is one of the most common minerals that contain manganese. You can often find it with other manganese minerals like manganite.
It forms in places where there is a lot of oxygen, such as in hydrothermal deposits (where hot water flows through rocks). It also appears in bogs, which are wet, spongy areas of land. Sometimes, pyrolusite forms when another mineral called manganite changes over time.
What Pyrolusite Is Used For
Pyrolusite has many important uses in industry and everyday life.
Making Manganese Metal
The metal manganese is taken out of pyrolusite. This is done by using other metals like sodium, magnesium, or aluminium to pull the oxygen away from the manganese. Another way is through electrolysis, which uses electricity to separate the elements.
Uses in Steel and Alloys
Pyrolusite is widely used to make special types of iron and steel, such as ferromanganese. These are important for making strong and durable steel. It is also used to create other metal mixes, like manganese-bronze.
As an Oxidizing Agent
Pyrolusite is a good "oxidizing agent." This means it can take electrons from other substances.
- It is used to make chlorine gas. In fact, chlorine gas was first discovered in 1774 by Carl Wilhelm Scheele when he mixed pyrolusite with hydrochloric acid.
- It helps make disinfectants, like permanganates, which are used to kill germs.
In Batteries
Natural pyrolusite was once used in batteries. However, modern, high-quality batteries now use a man-made version of manganese dioxide because it works better.
Coloring and Decolorizing
Pyrolusite has a unique ability to change colors:
- Decolorizing Glass: When pyrolusite is mixed into melted glass, it helps remove green and brown tints. It does this by changing the iron in the glass, making the glass clearer. This is why glassmakers found it very useful.
- Coloring Material: It is also used as a coloring agent. It can give violet, amber (yellow-orange), and black colors to glass, pottery, and bricks. It is also used in making green and violet paints.
Related pages
See also
In Spanish: Pirolusita para niños
