Not all of the jewellery is good for your health. There are materials from which jewellery is made that can cause alergic reactions, for exemple:
It is very common problem, especially in highly developed countries. Jewellery made from such a materials sometimes can cause serious skin diseases for exemple eczema.
If you want to avoid this, you should wear jewellery made from silver, gold or other skin friendly materials. You can find it here – jewellery.
Material that is especially good for health is amber or rasin.