Final answer:
The claim that olivine and quartz are commonly found together in the same igneous rock is false because they form under different conditions and are typically not present in the same rock type.
Step-by-step explanation:
The statement that olivine and quartz are commonly found together in the same igneous rock is false. Quartz is a major component in felsic (or silicic) rocks which are generally rich in silica, like granite or rhyolite, that form at lower temperatures. On the other hand, olivine is typically found in mafic or ultramafic rocks, like peridotite or basalt, which are silica-poor and form at much higher temperatures. These two minerals have different formation conditions and are normally not found together in igneous rocks because quartz melts at a much lower temperature compared to olivine. Therefore, when you see quartz in an igneous rock, it suggests that the rock cooled slowly enough to allow the quartz to crystallize out of the melt, indicating a more felsic composition.