Final answer:
Devil's Tower in Wyoming is composed of igneous rock named phonolite porphyry with hexagonal columns, made up primarily of feldspar and quartz, while containing minerals like hornblende and biotite.
Step-by-step explanation:
True, Devil's Tower in Wyoming does consist of igneous rock that has cooled and formed into hexagonal columns. This majestic geological feature is an example of an igneous rock type known as phonolite porphyry, which is recognized by its characteristic large, well-formed crystals embedded in a finer-grained background, or groundmass.
The specific composition of this igneous rock is primarily coarse-grained, including minerals such as feldspar and quartz, with smaller amounts of other minerals like hornblende and biotite. The hexagonal columnar structure, which is a distinctive trait of this rock formation, results from the way the molten rock cooled and contracted, forming geometric patterns in the process.