Think of the purpose you want it for, and see if you feel attracted to it. Be more concerned with how it feels than how it looks. Allow the crystal to pick you by interacting with it in this way. And remember to go with your initial feeling. If you need a specialized type of crystal to work with, consider one of the types described below.
Quartz crystals exist in a number of varieties.
In particular, some forms of quartz have different numbers of edges surrounding the largest of the faces that slope toward the point. A quartz crystal with six edges on the largest face is the most usual type. It acts as a comprehensive amplifier of energy in that it strengthens all of a person's energies or human qualities. In addition to the general characteristics mentioned above, quartz crystals sometimes have other special attributes that enhance their power. To identify these special types of crystals, pay particular attention to the largest of the faces that slope toward the point.