rockm

"can I use this, is there any way to screen it to remove stones and big grit and then bake it in a fire ?"

Potters use collected clay all the time.

However, even if you have a supply, you still have to fire it at extremely high temperatures to make it usuable for a bonsai pot. You cannot get around having to have a kiln for this. Baking in a kiln at extremely high temperatures causes molecular changes in the clay, essentially melting molecules back into solid rock (or rock-ish) form. Clay is sediment from rocks.

You cannot achieve that kind molecular change at 500 degrees in your oven. You will simply get dried dirt that will dissolve --in a few minutes or a few days--when water hits it.

Advertisement