Add Yahoo as a preferred source to see more of our stories on Google. Gardener with basket of egg shells spreading crushed shells around tomato plant - VH-studio/Shutterstock A quality eggshell ...
A quality eggshell contains about 2.2 grams of calcium carbonate, the compound that gives them their strength. Eggshells also contain lesser amounts of magnesium, phosphorus, iron, copper, and ...