Lapis lazuli is a lazurite-rich metamorphic rock used as a gemstone and ornamental material.

Lazurite is a blue feldspathoid mineral and the key color component in lapis lazuli.

Durability is part of the appeal of Royal Blue Sapphire, not merely a technical footnote. That combination of blue body colour, 9 Mohs hardness, and vitreous lustre is what usually makes it recognisable in practice. The secondary royal blue note often matters more than people expect when separating it from lookalikes.

Sodalite is a blue feldspathoid mineral commonly used as an opaque ornamental gemstone.