With only an elementary school education, Garrett Morgan, born in Kentucky on March 4, 1877, began his career as a sewing-machine mechanic.
The most abundant elements in the Earth's crust are oxygen (46.6%) and silicon (27.7%). Minerals which combine these two elements are called silicates, and combined they are the most abundant minerals on the Earth. The silicates can be organized in terms of their chemical compositions and their crystal structures (indicated by the existance of cleavage planes). They most often contain members of the Big 8 elements.
Over 90% of the Earth's crust is composed of silicate minerals, making silicon the second most abundant element in the Earth's crust (about 28% by mass) after oxygen.