What is the difference between colloidal and ionic silver?

Colloidal silver is basically a very loose "umbrella term" covering many kinds of liquid, silver-based products, including particulate silver, ionic silver, silver protein, silver citrate, silver nitrate, and others.

Some people refer to the "particulate" silver solutions as "true" colloidal silver, because these solutions are composed chiefly of metallic silver particles which are suspended in a solution of pure distilled water - in essence, the very definition of a colloidal solution.

The silver particles in such a solution are composed of clusters of silver atoms. The atoms in a silver particle remain held together by "Van Der Waals' force of attraction that causes identical atoms to be attracted to each other.

On the other hand, ionic silver is a solution consisting of water and single atom silver ions, as opposed to clusters of single atoms.

A particulate silver solution generally contains up to 90% or more silver particles, while an ionic silver solution generally contains up to 90% or more silver ions.