What is Ion and why do Ion brushes help hair that has suffered environmental damage?

An Ion is an atom that has lost or gained one electron making it negatively or positively charged.

Volcanic Andosite quartz crystals emit negative ions and when added to resin can be formed into brushes. This produces brush quills that have a safe natural energy when used in brushing which has been proved to have restorative benefits on hair. The capillary vessels become stimulated and the cuticle layer is tightened which seals in natural oils, helps to promote hair growth, and leaves hair soft, smooth, and vitalized.