Polished black obsidian points are six sided, and polished. Crystal points are often used to direct energies through the apex of a point.
This black natural glass has been formed from the rapid cooling of lava. Because it is easily splintered into sharp fragments, obsidian has long been used in making knives, arrowheads and sculptures.
In healing circles, it is known as a stone of protection with grounding properties, it is often used to clear subconscious blocks and to absorb and disperse negativity.