Earth Science Rocks & Minerals Science for 4th Grade Rocks contain valuable minerals. An ore is a rock rich in valuable minerals that can be removed from the Earth’s crust. Workers use machines to dig out the ore. Ore has valuable minerals The iron from hematite is used for things made of steel. Ore has valuable minerals Gypsum is a white mineral used to make paint and plaster. Ore has valuable minerals Halite is rock salt used to make ice cream. Ore has valuable minerals Copper is a metal found is rock formed from lava and other places. Ores can protect us. Lead is a metal from galena and used in aprons to protect us from harmful radiation in x-rays.