Azurite

Azurite is a deep blue mineral, often associated with malachite due to its tendency to transform into it over time. Composed mainly of copper, carbonate, and hydroxide, it forms in the oxidation zones of copper deposits. Historically, it was used by the ancient Egyptians as a pigment for frescoes and amulets, while medieval alchemists considered it a stone capable of opening the mind to hidden truths.