Charcoal can be used in many ways, drawing sigils, circles, painting and drawing for magical purposes.
Element: Air, Earth, Fire
Deities: Haashchéezhini (Black God)
Power: Banishing, Healing, Protection
Candle Color: Black, Dark Grey
Uses: concentration, bringing groups together to unite, gain, community, wealth, money, prosperity, purifying, cleansing.
By placing a piece of charcoal wrapped in paper (tissue, etc) in your pocket it protect you from the evil eye, curses, negative spirits, psychic attacks.
Place 3 pieces of charcoal under your bed while sleeping for above reasons.
Also remember by burning wood on certain days, (such as Yule, Samhain, Beltane, full moons, etc.) Or certain woods will draw that energy into the charcoal and bring certain properties energy to spells and rituals in your craft.