Answer:
silicate
Explanation:
The silicate class of minerals makes up 90 percent of the Earth’s crust, and is compounds of silicon and other chemical elements. The two most common silicate types found in the Earth’s crust are quartz and feldspar minerals. Quartz, also called silicon dioxide, contains silicon and oxygen and has types that are both clear and colored, such as:
rock crystal
amethyst
citrine
