Chemical weathering in which chelates draw metallic cations (positively charged ions) out of rocks and rocky minerals. Ultimately, all forms of weathering have a hand in forming soils. Also: a controversial medical procedure in which the organic chemical EDTA is injected into the body to chelate heavy metals from the blood. The list of claimed benefits includes help for atherosclerosis and various kinds of vascular disease, decreased angina, nicer skin color, healing of gangrene, better blood viscosity and circulation, fewer free radicals, smoother cell and organelle functioning, heightened sensuality, healed ulcers, diminished arthritis, MS, Parkinon's, and Alzheimer's, and of course slower aging. Proponents whose praises for chelation are ignored claim to be victims of the medical establishment, their clinking heavy metals chelated by a disbelief freely played if not always radical.