What is the primary mineral composition of Peridotite?

Peridotite is primarily composed of olivine and pyroxene, making this option the most accurate representation of its mineral makeup. Olivine is a magnesium iron silicate that characterizes peridotite, and it typically comprises a large portion of the rock, often more than 50%. Pyroxene, particularly the types known as clinopyroxene and orthopyroxene, also forms a significant part of the rock’s structure. This mineral composition classifies peridotite as an ultramafic rock, which means it contains a low percentage of silica and high levels of iron and magnesium.

The other options involve different groups of rocks or mineral compositions that do not relate to peridotite. For instance, quartz and feldspar are common in more felsic rocks like granite, while basalt and gabbro are mafic and are different in mineral composition compared to peridotite. Granite and diorite, likewise, are also composed primarily of quartz and feldspar, which are not characteristic of peridotite. Thus, the choice of olivine and pyroxene correctly identifies the unique attributes of peridotite.