Minerals are naturally occurring inorganic compounds that make up the Earth's crust. They include metals like iron and copper as well as non-metals like salt and gypsum. Mineral resources can be divided into fuel minerals like coal and oil, and metallic and non-metallic minerals. Metallic minerals contain metals while non-metallics do not. Mineral resources are vital for industries and development but overexploitation can lead to environmental problems like pollution, depletion of resources, and degradation of land. Conservation efforts include sustainable mining practices and reducing waste.