What defines a silicate mineral?

A silicate mineral is defined by its composition, which includes the presence of silicon and oxygen in its molecular structure. The basic building block of silicate minerals is the silicate tetrahedron, which consists of a silicon atom surrounded by four oxygen atoms. This tetrahedral structure can link together in different ways to form a wide variety of silicate minerals, making them the most abundant group of minerals in the Earth's crust.

The presence of silicon and oxygen is fundamental to the classification of a mineral as a silicate, as these two elements are what primarily characterize this group. Silicates include important minerals such as quartz, feldspar, and mica, each exhibiting various properties and structures derived from the way their silicon-oxygen tetrahedra are arranged.

Understanding the building blocks and structure of silicate minerals helps distinguish them from other mineral groups, each defined by different elemental compositions. In contrast, the other options do not align with the defining characteristics of silicates; they reference different combinations of elements that do not reflect the essential silicon-oxygen framework of silicates.