Product Description: Ultra-pure (~99% magnesium carbonate), high-performance chunky chalk is made from the mineral contents of seawater. No destructive mining here! This chalk is a byproduct of the salt industry and is produced using natural processes such as solar evaporation. This, combined with our plant-based packaging (which is also fully recyclable. leads to a lower energy and environmental footprint vs. other chalks. Features: highest purity magnesium carbonate (~99%) rosin free no fillers plant based packaging non-mined super grippy