According to a Commercial Product Report by silver-colloids.com [ 48. silver colloids ]  [ a site that provides detailed laboratory analyses of colloidal silver products ], there are three distinctly different types of silver products on the market that use different formulae, are all labeled and sold as "colloidal" silver. In addition to this source, there are four more kinds of silver that should be included as information about silver: [ 14. Dr. Marcola ]  [ 10.Colloidal silver ]

Kinds of Silver:

1. Silver sol: ASAP Antibacterial Silver Wound Dressing Gel, was approved in November, 2009, by FDA as a prescription 510(k) medical device. It is made by a new technology that distinguishes silver sol from colloidal silver and all other silver products. ASAP silver sol has also been approved as a nutritional supplement. 
   
   

2. Ionic silver: contains such a lower percentage of silver particles than true colloidal silver, these products will not be as effective as true colloidal silver. [ 10. Colloidal silver list of diseases: ]  [ 81. CSL: Silver colloids product reports ]

   Problem with ionic silver [ with one positive electron in outer shell: refer to photo on right ] is that it combines with chloride to form chloride ions. "Once silver chloride is formed in the human body, it does not dissolve; hence silver is not available to be used on pathogens. All ionic silver will turn into silver chloride [ a salt ] once inside the body because of the readily available supply of chloride ions in many different forms. Silver chloride is eliminated by the kidneys and expelled through the urine." [ 10. Colloidal silver list of diseases: ]

Silver ions combine with chloride ions to form silver chloride Silver nano-particles do not form silver chloride!

3. Silver protein:   Silver protein products are the second most prevalent type of so-called colloidal silver products on the market. These products are a combination of metallic silver particles that are very large compared to nano-particles. Silver proteins settle to the bottom. To prevent the settling out, an additive protein binder   is used to keep the particles in suspension. If the description of the silver product claims to have high concentrations of colloidal silver (typically in the range of 30 to 20,000 ppm), then you can suspect that it is a protein silver. You want to avoid all silver protein products. [ 14. Dr. Marcola ] Silver protein products have the lowest particle surface area for a given silver concentration, making the silver protein inaccessible for safe and effective absorption by your body. Because of this, you want to avoid all silver protein products. [ 14. Dr. Marcola ]   [ 80. CSL: Silver colloids product reports & test ]

4. True colloidal silver:   true silver colloids do not cause argyria & have no side-effects.

   "Colloidal silver is made up of tiny nano-particles of metallic silver. The particles are complete and do not combine with other elements. Because these are super small microscopic in size, they are not affected by the pull of gravity and do not settle down.

5. Silver Particles: There is a negative surface charge (voltage measured as Zeta) on metallic particles, that keeps them separated, due to repulsion between like charged particles. While the smaller particles are too light for gravity to take control, the very large particles mentioned will settle out quickly, due to gravitational pull overcoming the van der Walls, electrostatic and other suspension forces.

6. Silver salts: caustic and damage human tissue; used in photography. The silver-salt products, recorded to have caused argyria [ bluish colored skin ], contained concentrations of silver that were over 3,000 times the concentration found in colloidal silver products. [ 31. Juniper ]  [ 80. CSL: Silver colloids product reports & test ] Avoid all silver salt products.

7. Silver metal: as raw mineral; various indispensable uses in industry. [ 67. Wikipedia ] Silver is used in industry, photography, jewelry & silverware.