RE:RE:RE:RetiredgeoMagnetite is a rare accessory mineral in granites. It is far mare common in Anorthosites and mafic rocks like gabbro. Anorthosites can be considered granitoids even though literally they are not.
Drill core logs are of highly variable quality. Core loggers tend to be junior employees. "if it has lots of feldspar it is a granite" . Countertop people use the same geological classification.