This product has a wonderful Calcium content.  It has proven itself to be a useful longer lasting liming material that has some other amazing attributes.  It high surface area makes it a great structure in soil for soil microbes,  It holds onto soil nutrients like Nitrogen and reduces leaching.  It also helps store more water in soils.  We use it in conjunction with the Basalt Minerals and have had tremendous success in the landscape with lawns and food gardens.