2018Minerals and Rocks - First Day Cover

The science that explores the creation and classification of rocks is called petrology, and the science that explores the minerals rocks consist of is called mineralogy. Rocks make up the solid part of the Earth called lithosphere, and it encompasses the crustand the uppermantlereaching the depths of 100 kilometres. Below the lithosphere there is 2,900 kilometre thick outer core. The inner core reaches the depth of 6,370 kilometres to the centre of the Earth.