Shungite contains a high amount of carbon, which gives the stone its deep, matte-black colour. Both polished and raw shungite can leave dark marks on skin or fabric. This is a natural property of the mineral, not a sign that the item is damaged or poorly made. Slight staining is possible, especially where the pendant rubs against skin, a collar or other clothing.
If you plan to wear white or light-coloured tops, keep in mind that the pendant may leave a greyish or blackish mark over time, particularly on warm days when you perspire. These marks usually wash off skin easily with mild soap and water. For fabric, treat the mark as you would a graphite or carbon stain, and check the garment’s care label before cleaning.
To reduce transfer, try to position the pendant so it does not rub constantly against the same spot, and wipe the stone clean with a dry, soft cloth before wearing. The tendency can lessen as loose surface particles wear away, but it may never disappear completely because the carbon content is an inherent part of the stone.