Safflorite: The mineral safflorite information and pictures

About

Safflorite belongs to the Loellingite group, which is a group of chemically related isomorphous minerals that are all rare. Other members discussed in this guide are Loellingite and Rammelsbergite. Safflorite oxidizes to form the pink cobalt mineral Erythrite. Safflorite may also form as a pseudomorph of Silver.

Identification

Chemical Formula: CoAs₂
The above is the formula of pure Safflorite. However, since it usually occurs with some iron replacing the zinc, its formula is more accurately described as (Co,Fe)As₂.
Composition: Cobalt arsenate, usually with iron, sometimes with some nickel. If the cobalt (Co) is replaced by more than 50% nickel (Ni), the mineral is not Safflorite, but Rammelsbergite, and if it is replaced by more than 50% iron (Fe), the mineral is Loellingite.
Color: Silver-white. Tarnishes dark gray.
Streak: Black
Hardness: 4.5–5.5
Crystal System: Orthorhombic
Luster: Metallic
Cleavage: Indiscernible
Fracture: Conchoidal
Tenacity: Brittle
Transparency: Opaque
Specific Gravity: 7.0–7.3
Group: Sulfides; Arsenides
Rock Type: Sedimentary, Metamorphic

Rankings

Popularity (1–4): 4
Prevalence (1–3): 3
Demand (1–3): 3

Crystal Forms & Aggregates

Occurs only in very small tabular crystals, which are usually twinned and compacted together. Also occurs massive, grainy, fibrous, dendritic, radial, and in coxcomb aggregates.

Striking Features

Color and tarnish, crystal habits, hardness

Environment

Occurs in hydrothermal veins of moderate temperature and pressure, often in Silver deposits.

Noteworthy Localities

Safflorite is a rare mineral with few occurrences. It was found in Germany in Wittichen, Black Forest, Baden-Wurttemberg; and in Schlema-Hartenstein and Schneeberg, in the Erzgebirge, Saxony. It was also found in the Lill Mine, Pribram, Bohemia, Czech Republic; Bou Azzer, Morocco; the Castle and O'Brien Mines, Cobalt, Timiskaming District, Ontario, Canada; and the Olafsen Iron Mine, Hereford Township, Berks Co., Pennsylvania.

Common Mineral Associations

Arsenic, Erythrite, Calcite, Silver

Distinguishing Similar Minerals

Arsenopyrite - Greater hardness.
Skutterudite, Loellingite, and Rammelsbergite - Greater hardness.
Pyrite, Marcasite, and Pyrhottite - Occurs in different crystals, more yellow in color.