In other words: What are these mysterious properties that they have other then sparkling beauty and varied color?
Crystals and minerals have been used by many cultures throughout time for medicinal and other purposes. The ancient Egyptians and Native Americans would bury their dead with quartz crystals. In ancient Greece, hematite was used as protection for soldiers in battle and bloodstone to staunch bleeding. Even St. Hildegard of Bingen describes the use of crystals and minerals for their healing properties in her classical book, Physica.  

How does this happen?

More than 70% of the elements in the Periodic Table conduct electricity. Everything on earth is made up of elements in the Periodic Table, elements being made of only one type of atom. That means most things on earth, crystals and minerals included, can conduct some amount of electricity and often maintain it, however meager.

Crystals and minerals simply have an inherent energy frequency due to their particular composition.

Because most things can conduct energy on some level, it helps explain why you can “feel someone” in an object or item they’ve held close for a long time. Or perhaps you can “feel an event” like an argument in a room, long after it happened. The energy frequencies of the individuals involved magnetized the article or location much the way a magnet will magnetize iron if it is near it for a period of time.