The powers of crystals were attributed to them by ancient esotericists and magicians. This can easily be misunderstood as a claim that the minerals do have special energies. Actually, the magicians found that certain stones and metals were harmonious with certain categories of magickal force. The best example is Astrological.
Astrologers place different attributes under the headings of the various planets and Zodiacal signs.
Astrological symbolism serves as a means of categorizing the nature of things based on their appearance and inherent capacities. Technically, these are tables of correspondences. Certain materials were found to be good vehicles for containing magickal force. Quartz is one such mineral. Consider that quartz crystals were used in radios and the manufacture of watches and similar devices.