▎ 摘　　要

NOVELTY - A nontoxic dustless chalk comprises 15-25 pts. wt. gypsum powder, 10-20 pts. wt. magnesium carbonate, 10-20 pts. wt. titanium pigment, 5-10 pts. wt. activated clay, 3-6 pts. wt. medical stone powder, 1-5 pts. wt. plant pigment, 0.5-2 pts. wt. nano graphene, 1-4 pts. wt. borax, 1-4 pts. wt. Aloe and balance water. USE - Nontoxic dustless chalk. ADVANTAGE - The product has smooth and clear writing, and has proper hardness.