The crystal is a variation of a channeling crystal.
A channeler has at least one face with seven sides and one with three sides. The number seven represents intuition and spiritual connection; while three represents the grounding of this connection (much as a pyramid grounds spiritual energy), and the ability to express it.
While it is possible for one to channel a nonphysical entity after practice with this crystals, that need not be the goal. It can also help us awaken and access our own intuitive knowledge, especially when we have a problem we can't solve through usual reasoning patterns.
In a Dow crystal the termination has three seven-sided faces and three triangles. This means that the energies described above are perfectly balanced.