What Minerals Make Up the Earth's Surface?

Features

Four things must be true in order for a nonliving thing to be classified as a mineral. Minerals must occur naturally, so synthetic materials cannot be minerals. Minerals must never have been alive, so fossil fuels like oil and coal are not minerals. Wherever the substance is found, there can be no change to its chemical structure in order for it to be classified as a mineral. Finally, the atoms in minerals are always arranged in crystals.

There are 3,000 minerals found on the earth's surface, of which 100 are considered to be common minerals. The most commonly found minerals belong to the silicate mineral family, accounting for 75 percent of the composition in the earth's crust. Quartz, pyroxene, amphibole and feldspars are silicates because they contain silicon and oxygen. Common feldspars include silica, aluminum, calcium, sodium and potassium.

The second most common family of minerals on the surface of the earth are carbonates. These include calcites like limestone, carbon, oxygen and dolomite. Magnesium is another mineral found in dolomite rocks.

Some of the minerals found in the crust or surface of the earth are metallic compounds. Eight percent of these metal minerals are aluminum; 5 percent are iron, and 4 percent are calcium. Copper, gold, mercury, platinum and nickel are rarer metallic minerals found on the surface of the earth. A "rare earth meta,l" cerium is the 25th most commonly occurring mineral.

The first person to write a scientific study of minerals was Theophrastus, a Greek who lived around 300 BC. The next person to take on the subject in writing whose work has endured through the years was Pliny the Elder, a Roman who lived in 77 AD. In 1854, James Dana organized a classification system that continues to be used to group minerals. It has 78 classes. In 1941, a different system for classifying minerals was devised by Hugo Strunz that uses 10 classes. These allow geologists and rock hounds to easily identify the minerals they find according to their properties and attributes.