The Mineral sphaerocobaltite

Sphaerocobaltite describes a pure cobalt carbonate, without calcium. Pure Sphaerocobaltite is quite uncommon, as the cobalt is usually mixed with calcium. This leads to confusion with the term Cobaltocalcite. Cobaltocalcite refers to an intermediary mineral between Calcite and Sphaerocobaltite in a solid solution series. It may be described as either a cobalt rich variety of Calcite, or a calcium rich variety of Sphaerocobaltite.

Sphaerocobaltite belongs to the calcite group of minerals, a group of related carbonates that are isomorphous with one another. They are similar in many physical properties, and may partially or fully replace one another, forming a solid solution series. All members of the calcite group crystallize in the trigonal system, and have perfect rhombohedral cleavage.

Chemical Formula	CoCO₃
Composition	Cobalt carbonate, usually with some calcium
Variable Formula	(Co,Ca)CO₃
Color	Intense pink to reddish-white. Oxidizes brown, dark red, dark maroon, or black.
Streak	Reddish-white
Hardness	3.5 - 4
Crystal System	Hexagonal
Crystal Forms and Aggregates	Occurs in small rhombohedral crusts and massive.
Transparency	Transparent to Translucent
Specific Gravity	4.13
Luster	Vitreous
Cleavage	1,3 - rhombohedral
Fracture	Conchoidal
Tenacity	Brittle
Complex Tests	Effervesces in hydrochloric acid
In Group	Carbonates; Calcite Group
Striking Features	Deep pink and red color.
Environment	In secondary ore veins rich in cobalt and nickel.
Rock Type	Metamorphic
Popularity (1-4)	3
Prevalence (1-3)	3
Demand (1-3)	3

Sphaerocobaltite AUCTIONS

OTHER NAMES

Spherocobaltite

VARIETIES

Cobaltocalcite

- Cobaltocalcite refers to an intermediary mineral between Calcite and Sphaerocobaltite in a solid solution series. It is most often perceived as a cobalt-rich variety of Calcite with a rich pink color. (Cobaltocalcite may also be mistakenly used as a synonym for Sphaerocobaltite).

NOTEWORTHY LOCALITIES

Sphaerocobaltite is a rare mineral. The original type locality is the Daniel mine in Schneedberg, Saxony, Germany. The Kolwezi Mines in Shaba (Katanga), Congo (Zaire) are the most abundant and outstanding source for this mineral. Other occurrences are Bou Azzer, Morocco; Santa Rosalia, Boleo, Baja California, Mexico; and the Cobre Mine, Conception del Oro, Zacatecas, Mexico.

COMMON MINERAL ASSOCIATIONS

Calcite, Dolomite, Malachite

sphaerocobaltite PHOTOS