A "colloid" is a chemical description of a gel-like suspension. Colloidal minerals are a blend of minerals found in some form of suspension or solution. Generally, commercially available colloidal minerals are produced from mining ancient sea beds, and then mixing the mined minerals with water or other fluid to hold them in solution. While these products provide a large number of minerals, there is no credible scientific evidence to support marketing claims for superior absorption or bioavailability. They may even contain relatively high levels of unwanted minerals, such as aluminum, lead, or mercury...or other contaminants. Fewer than 20 minerals are currently known to be essential for humans. The exact role of other trace elements, as well as our intake of these micronutrients from food, remains to be clarified.