Here's a breakdown:

* Silica (SiO2): The most abundant component in igneous rocks. It forms the framework of the rock structure.

* Other Oxides: In addition to silica, igneous rocks contain other oxides like aluminum oxide (Al2O3), iron oxide (FeO), magnesium oxide (MgO), calcium oxide (CaO), sodium oxide (Na2O), and potassium oxide (K2O). These oxides contribute to the rock's color, texture, and other properties.

The proportions of these compounds vary, leading to different types of igneous rocks. For example:

* Felsic rocks: High in silica (60% or more). They are typically light-colored and include granite and rhyolite.

* Mafic rocks: Lower in silica (45-55%) and richer in iron and magnesium. They are usually dark-colored and include basalt and gabbro.

* Ultramafic rocks: Very low in silica (<45%). They are very dark-colored and include peridotite and dunite.

So, while igneous rocks are primarily composed of silica, the presence and proportions of other oxides significantly influence their characteristics.