How should I care for an unpolished shungite pendant? — Unpolished Pearl Pendant, 20 mm

The product card has no information about caring for the pendant — see the packaging. General tips for caring for jewellery made of natural stone (not a manufacturer's instruction): take the pendant off before showering, swimming and washing your hands; apply perfume, creams and lotions before putting the jewellery on; if necessary, wipe it with a soft dry cloth, without abrasives or chemical cleaners; keep it apart from metal jewellery so that it does not get scratched.

What is supplied with it (a cord or a chain), the length and the method of fastening are not stated on the product card — check this before buying.