1. Feldspar: This group of minerals comprises about 60% of the Earth's crust. They are found in various types of igneous, metamorphic, and sedimentary rocks.

2. Quartz: Making up around 12% of the Earth's crust, quartz is a very common and durable mineral, often found in various forms like sand, sandstone, and granite.

Together, feldspar and quartz make up a significant majority of the Earth's crust.