The correct answer is D. All of these.
Porcelain is a type of ceramic that is made from a mixture of clay, feldspar, and quartz. The clay provides the plasticity that allows the porcelain to be shaped, the feldspar provides the flux that lowers the melting point of the mixture, and the quartz provides the strength and durability of the finished product.
Clay is a fine-grained, earthy material that is formed by the weathering of rocks. It is composed of minerals such as kaolinite, illite, and montmorillonite. Clay is used in a variety of products, including pottery, bricks, and concrete.
Feldspar is a group of minerals that are composed of aluminum silicates. Feldspar is the most abundant mineral in the Earth’s crust. It is used in a variety of products, including ceramics, glass, and fertilizer.
Quartz is a mineral that is composed of silicon dioxide. Quartz is the second most abundant mineral in the Earth’s crust. It is used in a variety of products, including glass, ceramics, and electronics.