A variety of minerals - galena, calcite, pyrite, azurite, orpiment and rhodochrosite. Galena (the gray cubes) is the most important ore of lead. Pyrite, popularly known as fool's gold, is an important source of sulfur. The blue azurite is an ore of copper, and the yellow orpiment contains arsenic. The white calcite and the pink rhodochrosite are both carbonate minerals. Rhodochrosite gets its pink color from manganese.