I'm not an expert of precious stones or crystals, and last Sunday was the first time i've heard of shungite. I met one of my friends at a meetup in the Pilis mountains who is a merchandizer of stones and crystals.

He has shown me this stone and i felt i had to buy it immediately. To tell the truth, i've never heard of shungite yet. He said it is very rare and can only be found in Karelia. It is used as a healing stone for many thousands of years.
It's carbon content is about 98-99%, with some silicate. Its structure is not usual, called fullerene with a sphere form which is a nano-particle.

(source: https://nanografi.com)

Shungite for health:

Very strong antioxidant! Shungite-containing mineral water is effective in the treatment of diabetes in the body, cardiovascular diseases, gastrointestinal disorders, mental disorders, upper respiratory tract disorders, liver, joint, spinal and skin disorders. Shungite normalizes blood pressure, relieves headaches, insomnia, eliminates chronic fatigue syndrome, elevates the general condition of the body.

Shungite for the soul:

It is a stone that has a strong earth connection that mediates ancient legacy and means to bring the mystical energies of ancient earth into our daily lives. Like most black stones , this is a strong stone, it supports earth contact.
A piece of sungite stone, a pendulum worn in a necklace, can radiate energy, it seems to resonate strongly from the quartz in stone. This is an effective tool, as a general protection shield, which protects against electromagnetic radiation from electrical equipment, including computers, mobile phones, microwave ovens and televisions.