book does not talk! ...and it's so important !!!
When you wear a stone pendant, if you want to get his benefits should be rinsed under water daily 10 seconds and wipe with a clean towel morning and evening ... why? Because in the skin (where it should be for the benefits) of sweat and grease deposited on the stone and make a "screen" the passage of ions into the skin cells. (Do not forget that cells are equipped with "ion channel" for example creams or clay mud spa etc. ...). If you leave this screen between the stone and your cell nothing happens! ... we must also clean the area of your skin or stone based (not cream, skin clean).
Of course the water purifies the stone and the sun recharge (think silicon solar panel that captures solar energy and transforms it into household energy).
Think of your stone as the hygiene of your body.