Abrasives for polishing processes tend to be chosen according to the desired material removal rates. Common grit sizes are around 1 pm [MARI04, p. 442]. In rough abrasive pastes, the following abrasives with higher hardness are used [MARI04, p. 381, BORK92, p. 11, 13, 20, DAMB05, p. 33]:
• Diamond (C),
• Magnesia (MgO),
• Pumice (vitreous spongy compound formed after drying of volcanic lava),
• Beryllium oxide (BeO),
• Chrome oxide (Cr2O3),
• Iron oxide (Fe2O3),
• Garnet (class of minerals with the formula (Me3Me2SiO4)3, with Me" being Fe, Mg, Co, or Mn, and Me’" being Fe, Al, or Cr),
• Corundum (60-90 % Al2O3),
• Emery (60 % Al2O3 and Fe3O4, Fe2O3, SiO2),
• Quartz (SiO2 with CO2, H2O, NaCl and CaCo3 inclusions),
• Silica carbide (SiC), and
• Glass (Processed recycled glass has been sold as an abrasive blasting medium under several brand names in the United States).
Soft abrasives as the following are employed for fine polishing paste compositions [MARI04, p. 381 f., BORK92, p. 20]:
• Kaolin,
• Chalk (obtained from crushed, rinsed and washed limestone),
• Barite (barium sulfate),
• Talc (hydrous silicate of magnesium),
• Tripoli (white sedimentary mineral obtained after coagulation of silica gels in laminae compacted into soft rock mass), and
• Vienna lime (white powdery composite of fine-crystalline calcium and magnesium oxides, obtained after burning dolomite).