Magnesium carbonate is an absorbent due to the high porosity of magnesium carbonate. However, excessive absorption of perspiration may cause gumminess and streaking if there is too much magnesium carbonate in the formula. Magnesium carbonate may also cause drying. It removes the shine of talc. It is also a perfume carrier and slight opacifier. Too much magnesium carbonate will make a compact brittle because of the absorbency. It is decomposed by acids. (Sagarin 226-227,256). Kaolin (2SiO2Al2O3�2H2O) is an absorbent and removes the shine of talc. It also has soothing properties. Unfortunately, it causes many perfumes to deteriorate. Chalk is used as a perfume carrier. Only a small amount may be used as it tends to make compacts brittle (Sagarin 225-227,256).