Sanding blocks can be either mounted holders for sanding sheets or unitized abrasive blocks designed for deburring, blending, and finishing. Sanding sheet holders create a solid sanding surface and help prolong the life of sanding sheets. Sanding sheets are attached by clip-on tabs, PSA, or hook and loop. Unitized sanding blocks are solid blocks of varying grades from coarse to very fine. Common abrasive minerals include aluminum oxide, ceramic, diamond, and silicon carbide.