In my posts about making tooth powders and toothpaste, I list calcium carbonate as an ingredient. Don’t wanna buy it? You can make it yourself!
I prefer farm-fresh, free-range eggs.
Use your eggs as you normally would. I rinse off the egg white left over first and then store the shell in the carton for later use.
Once you have filled up your carton, rinse really well, removing any egg whites that may have been missed in the first rinse, but try not to remove the membrane, these have additional nutrients.
Boil 6 cups of filtered water in a stock pot
Carefully place them into the water
Boil for 10 minutes
Spread the shells on a baking sheet or baking pan and let dry overnight.
Pre-heat oven to 200 degrees
Bake for 10 minutes
Using a coffee mill, powder your baked eggshells
Store in a tightly sealed mason jar and keep them in cool dry environment (basement or pantry is fine)