MatsMatsMats.com Gymnastics Broken Chalk Pieces - 1 Box, 24-pound box containing chalk pieces Each 24lb box of chalk contains large chalk pieces. Improves your grip by absorbing the moisture from your skin. Made of magnesium carbonate white chalk. Ideal as gymnastics chalk, weightlifting chalk, or climbing chalk. Comes packed in a single 24lb bag/carton of loose, block pieces that are easily crushed to make powder.