^^^^^^ That ^^^^^^ +rep, good answer.Dolomite lime is calcium carbonate + magnesium carbonate. Standard agricultural lime, found in every hardware store and anyplace else that sells lawn-related chemicals, is usually just calcium carbonate and will work every bit as well as dolomitic lime. If your plants aren't suffering a Mg deficiency, use agricultural lime. It's so cheap you will have to buy much more than you need (it comes in big bags) but the stuff keeps forever. Just avoid hydrated lime and quick lime, those are different.