turquoise is an opaque, blue-to-green mineral that is a hydrated phosphate of copper and aluminum. turquoise has a lower-than-ideal hardness and durability for use in certain types of jewelry.
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.
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%).