... shown below: Hot-Pressed Diamond Drill Bit matrix and Rock Formation Comparison FormEarth PropertyRockBit Matrix TypeSoftShale, ... , etcSteps Shaped Type, Concentric Circles Type, Canine Tooth Shaped Type, Wheeling Gear Shaped TypeHardBasalt, gneiss, granodiorite ... and Dolomite Marble, Diopside Petrochemical Diorite, Mixed Carbide Powder Rocks, Biotite Hornblende Anorthosite, Pyroxenite through, ...