Aluminum oxide and silicon carbide are most commonly used bonded abrasives material.
There are nine materials below for reference.

Material:Brown alumina
Symbol:A
Color:brown
Usage: For carbon steel, alloy steel, malleable castiron, or hard bronze grinding and cutting.

Material: White alumina
Symbol: WA
Color: White
Usage: For fine grinding, dressing, honing, or screw grinding the tools of alloy steel, high speed steel, hardened steel, etc., with great strength and high hardness.

Material: Pink alumina
Symbol: PA
Color:Pink
For general grinding and coarse grinding the internal tools, gears, and instrument frame of alloy steel, tool steel, and hardened steel.

Material: Single crystal alumina
Symbol: SA
Color: Light Khaki
Usage: For grinding vanadium steel, austenitic stainless steel, high speed steel, titanium alloy, etc. with high hardness and strength.

Material: Micro crystal alumina
Symbol: MA
Color: Brown
Usage: For various of hardened steel, stainless steel, or nodular cast iron heavy grinding, mirror grinding, or coarsing grinding.

Material: Black silicon carbide
Symbol: C
Color: Black
Usage: For cast iron, non-ferrous steel, and non-metallic material grinding, cutting, or honing.

Material: Green silicon carbide
Symbol: GC
Color: Green
Usage: For brittle and hard carbide, glass, gem, and stone grinding, cutting, or super fine grinding.

Material: Synthetic diamond
Symbol: SD,SDC
Color: Yellow or green
Usage: For hard carbide, optical glass, gem, semi-conductor materials, non-ferrous materials, and non-metallic materials grinding, cutting, or electrolytic grinding.

Material: Cubic Boron Nitride
Symbol: CBN
Color: Amber, or black
Usage: For grinding ferrous metal, such as refractory alloy, vanadium steel, cobalt steel, molybdenum steel, high speed steel, bearing steel, and titanium steel, etc.