Discolouration is a completely natural property of classic (normal) shungite. This effect is stronger on unpolished surfaces and takes a relatively long time to wear off. Shungite with polished surfaces and precious shungite hardly discolour at all.
Shungite consists mainly of carbon and is relatively soft compared to other rocks.
However, carbon itself is not the reason for the discolouration. After all, natural diamonds are made of pure carbon and do not discolour, unlike a pencil lead, which is made of graphite (carbon) and does so.
Neither discolouration nor shungite itself is dangerous or toxic and does not pose a health risk.
Discolouration should in no way be considered a disadvantage of shungite; rather, it serves as a significant indication of the authenticity of this mineral. In the following, we would like to explain some examples of different applications of shungite to make it easier to use. A better understanding of the stone and its properties will make it possible to utilise shungite optimally.

Our examples are based on the high quality of the precious and classic shungite mineral that we have been offering our customers since the end of the 1990s. At the extraction site in Karelia, there are also shungite stones that are significantly softer or even harder. As these stones behave differently, we do not carry them in our range and do not wish to go into them in detail.

The discolouration of shungite jewellery:
Bead jewellery:
Although the surface of the shungite beads is polished, the drill holes are not. As a result, there may be some initial discolouration when worn, which unfortunately cannot be avoided.
Pendants:
With some pendants, not all surfaces can be polished, so these areas discolour more.
Engraved jewellery:
Engraving removes the polished surface, revealing unpolished areas. These areas initially discolour a little more.

However, these discolourations can be easily removed from the skin or from a blouse or shirt with soap and water. Over time, this effect will diminish considerably. My personal experience shows that a bracelet will no longer leave any discolouration after 2-3 weeks of wear. Of course, this depends on the design of the bracelet.
Please note that polished shungite jewellery should ideally not come into contact with water, as this can cause the shine to fade quickly. Depending on how often it is worn, the lustre will also fade considerably after approx. 2-3 months. However, this does not diminish the attractiveness of shungite jewellery, as matt surfaces are also very beautiful to look at. In combination with other materials or minerals, for example, the matt shungite beads are a particularly beautiful eye-catcher.

Colouring of shungite protective objects such as pyramids, spheres, cylinders, cubes etc.: 
Polished shungite pyramids, spheres or cubes are exactly the same as their counterparts with a matt surface. The only difference is that they are polished by an additional operation with a diamond disc. Protective objects with polished and matt surfaces are completely identical and just as effective. As the polishing process is omitted in the manufacture of matt products, they are slightly cheaper. Even if matt surfaces discolour strongly, this is not a sign of inferior quality. In fact, this is a natural property of the mineral and serves as an indication of its authenticity, among other things.
The only difference between polished and matt protective objects is that the polished pyramids, spheres and cubes are significantly less discoloured and the matt ones have no polish residue on the surface and can also be used for water treatment. Otherwise, this is really a matter of taste. With matt schungite surfaces, you can clearly see pyrite and quartz, which is particularly eye-catching. The polished surfaces have a deep, beautiful lustre. 
When choosing between matt and polished, it is advisable to bear in mind that the matt surfaces can be very discolouring at first and can leave lots of black fingerprints in the children's room, for example. 

Make the right choice between polished and matt shungite surfaces.
Matt surfaces of shungite spheres, pyramids etc. are very popular due to their natural appearance and versatility. People often opt for non-polished protective objects if they prefer a natural stone surface. This is also the right choice if the mineral is to be used for radiation protection and water treatment.

Polished surfaces, on the other hand, are an advantage if the protective object is touched more frequently. For example, if you want to use a sphere for rolling massages, take the pyramid with you on holiday or place the protective object in the children's room. In these cases, a polished surface is definitely more suitable, as the fingers or skin do not get as dirty when touched.

Discolouration of shungite rough stones during water treatment:
Only stones with a natural surface should be used for water treatment, as it is important that no foreign substances such as polish get into the water.
Classic shungite rough stone is relatively soft and strongly discoloured. It is important to rinse the stone well under running water before use; a plastic brush can be very helpful here. After cleaning, the stone discolours much less, but this cannot be completely avoided.
Precious shungite has a naturally shiny surface, so it hardly discolours at all. However, friction during transport can cause some dust to form. It is advisable to rinse the precious shungite stones thoroughly before use.
Discolouration from the raw stones, which may be visible as small black particles in the water, is completely harmless. They normally settle to the bottom of the container and the water then becomes completely clear.
It is very important that the water is completely clean and free of off-flavours after treatment with raw stones.

The discolouration of shungite is not a negative thing, even if this is often portrayed as a disadvantage on the internet. It is not to be expected that black streaks will appear from wearing shungite jewellery or that rough stones will smear in the hands like pieces of soft clay. However, you can be sure that if your shungite is slightly discoloured, this is a sign of authenticity. If the classic and precious shungite is of good quality and handled correctly, discolouration is not really a problem.

With these tips, discolouration is no longer an issue.

Schungite jewellery: Clean the jewellery before wearing it, this will significantly reduce discolouration. Be sure to wipe it with a dry cloth. Please do not use strong cleaning agents and avoid water, as this can quickly fade the shine of the jewellery.

Pyramids, spheres, cylinders, cubes etc.: Select a protective object with a suitable surface from the outset when purchasing. Always wipe shiny surfaces with a dry cloth and do not use cleaning agents or water. Matt surfaces are best cleaned under running water with a plastic brush. The protective objects will then discolour much less.

Classic shungite rough stones: These stones discolour strongly and should be cleaned thoroughly under running water before use. A plastic brush can be helpful here. Sufficient water and time are necessary in any case; afterwards they discolour significantly less. No cleaning agents should be used, especially if the stones are used for water treatment. Most dust can be removed from the stones very effectively with water and, if necessary, a brush.

Precious shungite: This special form of shungite hardly discolours at all, but dust is created by friction, especially during transport. It is advisable to rinse the precious shungite stones with water before use.

If the stones have already been carefully selected before purchase and thoroughly cleaned before use, the "discolouration of the shungite" is hardly worth mentioning.