Diatomaceous Earth (DE) is one of the richest sources of silica around, at ~80%. In comparison, Horsetail has ~4% (often touted as the highest source), and bamboo stalk has ~28%.
Silica is important for bones, hair, teeth, nails, ligaments and especially the skin. Silica is best absorbed with acid (stomach acid works quite nicely) as silicon dioxide must first convert to orthosilicic acid before it can be utilised by the body. Silica will convert to orthosilicic acid when in contact with water.
If you are making your own toothpaste, face cream, toner, nail treatment or moisturiser you should consider adding a small amount of DE as it will be very beneficial and is absorbed by your skin.
To supplement your daily intake of silica, here is a method on adding DE to water that I got from - http://www.mountainmistbotanicals.com/info/Silica_Diatomaceous Earth vs Horsetail Grass.htm (I am not afilliated with this site whatsoever, but this article is a really, really good read. If you are interested in Silica, DE or Horsetail I strongly recommend it.)
"...add a spoon full of food grade DE to a gallon of water and allow the DE to settle to the bottom. This may take a few days initially. Pour the water you intend to drink from the top of the container, but be careful not to disturb the DE on the bottom of the container. Refill the container with water and allow it to settle out again. Keep repeating this process. A spoon full of DE should last several years if it is not poured off in the water."
This method of adding DE will work especially well if you have a water urn/dispenser that has a spigot (tap) slight above the bottom - you can put a touch of DE in the bottom and it should supplement your water without any problems.
- Diatomaceous Earth must be food grade if you are considering using it for yourself, as many other posts have mentioned.
- DE contains ~2-4% aluminium oxide, so if you are avoiding all aluminium then do not consume this as a supplement. It should be known that orthosilicic acid reduced aluminium uptake in digestion as well as increasing the excretion of aluminium through urine. The DE water method above uses a very small amount of silica over a long period that it will minimize your ingestion of aluminium.
- Vegans/vegetarians generally should find DE acceptable, as it consists of phytoplankton (algae) but it is important to be aware of this just in case.