Diatomaceous earth is a powder containing about 80%-90% silica, made from the fossilized remains of diatoms. There are two main types of diatomaceous earth: food grade, which is suitable for consumption, and filter grade, which is inedible but has many industrial uses. It has been mined for decades and has numerous industrial applications.
All around the world there are ancient deposits of these diatoms which date back as far as 50 million years ago, although most commercial is from deposits that date back to 13 million years. It was first discovered in 1837 by a peasant in Germany, and was soon found to be an ideal abrasive for polishing metals and jewelry.
Diatomaceous earth is used:
- as pest control (non-toxic for humans, dries insects out)
- for abrasion
- for filtration (swimming pools, beverages, water purification)
- as dietary supplement.