Amorphous silicas suitable for use as abrasives in transparent toothpastes can be prepared by a precipitation route. These silicas are distinguished by having a BET surface area of 10 to 90 m/g, a weight mean particle size of 5 to 15 micron, and a plastics abrasion value of 16 to 26, a transmission of at least 70 % in the RI range from 1.430 to 1.443 and an oil absorbtion in the range from about 70 to about 150 cm/100 g.