Safflorite

(Co,Fe)As₂IMA symbolSaf^[1]Strunz classification2.EB.15aCrystal systemOrthorhombicCrystal classDipyramidal (mmm)
H-M symbol: (2/m 2/m 2/m)Space groupPnnmUnit cella = 5.173 Å, b = 5.954 Å
c = 2.999 Å; Z = 2IdentificationColorTin white, tarnishes to grayCrystal habitPrismatic crystals, massive to fibrousTwinningForms cruciform penetration twinsCleavageDistinct on {100}FractureUneven to conchoidalTenacityBrittleMohs scale hardness4.5–5.5LusterMetallicStreakGrayish blackDiaphaneityOpaqueSpecific gravity6.9–7.3References^[2][3][4]

Safflorite is a rare cobalt iron arsenide mineral with the chemical formula (Co,Fe)As₂. Pure safflorite is CoAs₂, but iron is virtually always present. Safflorite is a member of the three-way substitution series of arsenides known as the loellingite group. More than fifty percent iron makes the mineral loellingite whereas more than fifty percent nickel and the mineral is rammelsbergite. A parallel series of antimonide minerals exist.

Safflorite along with the other minerals crystallize in the orthorhombic system forming opaque gray to white massive to radiating forms, Clinosafflorite has a monoclinic symmetry. It has a mohs hardness of 4.5 and a specific gravity of 6.9 to 7.3. Twinning is common and star shaped twins are frequently found.

It was first described in 1835 from the Schneeberg District, Ore Mountains, Germany. Safflorite occurs with other arsenide minerals as an accessory in silver mining districts. It alters to the arsenate erythrite in the secondary environment.

• Minerals.net
• Mineral galleries
• Schumann, Walter (1991). Mineralien aus aller Welt. BLV Bestimmungsbuch (2 ed.). p. 223. ISBN 3-405-14003-X.