Scorzalite
Scorzalite ((Fe,Mg)Al2(OH,PO4)2) is a dark blue phosphate mineral containing iron, magnesium, and aluminium phosphate. Scorzalite forms one endmember of a solid solution series with the lighter, more magnesium-rich lazulite.
Scorzalite crystallizes in the monoclinic system in a dipyramidal form. It has a Mohs hardness of 5.5-6 and a specific gravity of 3.4. It is infusible and insoluble in water, and only slightly soluble in warm hydrochloric acid.