Lazulite and Siderite

Original Description: *Incomplete. Lazulite ((Mg, Fe)Al2(PO4)2(OH)2) can be deep blue, sky-blue or pale greenish blue. Lustre is vitreous to dull and streak is white. Hardness is 5 1/2 to 6 and cleavage is distinct in one direction. Lazulite usually occurs as bipyramidal or tabular but can also be granular or compact. Siderite (FeCO3) can be light to dark brown, reddish brown or white in colour. Lustre is pearly, vitreous or dull and streak is white or pale yellow. Hardness is 3 1/2 to 4 and cleavage is perfect in three directions forming a rhombohedron. Siderite usually occurs as rhombohedral with curved faces but can also be prismatic, scalenohedral, granular, cleavable masses, compact, massive, botryoidal or fibrous.