Shungite
Black is almost always the colour of protection in western magic. It is said to cloak the subject of the spell in darkness so that bad luck cannot find them.
The extremely dark colour of shungite makes it the ideal stone for practices surrounding hiding from bad luck.
Because of its electricity-conducting properties, it is also suitable as an amplifier in magic and meditation and in boosting the power of electromagnetic fields. Strangely it has also been reported that it can help boost weak wi-fi signals, too.
If you are working on focusing your mental energy towards a specific goal, shungite can act as a conductor of your energy. And it can drive it more strongly towards your desired outcome.
It can ground your energy and help keep it focused towards your goal, so that your energy doesn’t go ‘astray’.