Diatomaceous earth is 80 to 90% silica, with 2 to 4% alumina and 0.5 to 2% iron oxide.
Over 90% of the Earth's crust is composed of silica minerals, making silicon the second most abundant element in the earth's crust (about 28% by mass) after oxygen.
I dont use it, never saw what was so great about it.
I don't really feed it anymore (used to, but never saw any difference), but I do use the fool out of that stuff in my coop floor and bedding. I also sprinkle it on poop boards to keep poo from sticking.
Also when I have a hen go broody, I let her sit for about 3 days, then I sneak out at night and dust her and her nextbox with lots of DE. Every broody I've ever had used to get mites before I started doing this. I haven't had a problem with mites since.
I don't waste it in the feed. It is used in the horse and cattle world to keep feed from caking together in storage. I use DE in the litter to keep it dried out so I'm sure they're eating it but it isn't on purpose.
There is no proof it gets rid of intestinal worms when ingested as it only works well if its dry and their gut is always moist. It does seem to help externally though and I use it in the henhouse shavings, nest boxes and in their sand run to prevent lice an mites
I use it both in the dust bathing areas and the litter. Havent found a difference one way or the other, but it does wonders on snails that eat my hostas and lettuces in the garden. i like it better then using seven powder on the plants. Just dont like the idea of eating all the chemicals, alothough pretty much everthing from the grocery store is covered with them.