The mineral magnetite is iron oxide (Fe3O4), which is found in all three igneous, metamorphic and sedimentary rocks. This stone is often extracted from iron ore. Magnetite is also a mineral with the highest amount of iron (72.4%).

lapis lazuli, or lapis for short, is a deep-blue metamorphic stone used as a semi-precious stone that has been prized since antiquity for its intense color.