Crystals cut into the shape of a pyramid are effective for concentration, absorption, or deflection of energy, depending on the stone. Some believe that shungite, for example, neutralizes harmful electromagnetic fields by absorbing it. A pyramid shape allows for even absorption of energy on each surface. Obsidian is said to do the opposite, deflecting negative energy and sending it back to its source. And clear quartz, considered a purifying stone, is even more potent when cut into a pyramid shape, tightly focusing energy through the apex and focusing the properties of the crystal to a central point.