Stones: A look at how blue appears in stones and combinations of minerals. Lapis lazuli is known to be blue since ancient times and used for decorations. The Egyptians eventually figured out how to make Egyptian blue tiles. By grinding, heating and combining lapis lazuli with other substances, ultramarine blue was produced, a colour more valuable than its weight in gold. The act of alchemy would produce the next blue substance, Prussian blue. In modern days, a vivid blue would be accidentally created: YInMn Blue. And maybe one day, the mineral ringwoodlite that makes up much of the mantle is the earth could give another way to make blue.