The Mineral SPHAEROCOBALTITE
- Chemistry: CoCO3, Cobalt Carbonate
- Class: Carbonates
- Group: Calcite Group
- Uses: Very minor ore of cobalt and as a mineral specimen.
Specimens
The sometimes deep rose-red to pink color is very attractive and unique. It is easy to confuse sphaerocobaltite with two other carbonates; rhodochrosite and stichtite, because all three are described as red to pink minerals. However, side by side the color difference is obvious, as sphaerocobaltite has a more "hot pink" color than the redder pink of rhodochrosite or the more purple-pink of stichtite. Confused? Well, you just need to see them.
Sphaerocobaltite, fortunately, is further distinguished by its occurrences with cobalt bearing veins that have been affected by carbonated waters. It is found as crusts and small crystals in many cobalt ore locations around the world, but it is the mines of Shaba, Zaire that have produced the most outstanding specimens. Some specimens are draped with acicular dark green malachite crusts and the combination makes for a very colorful specimen.
PHYSICAL CHARACTERISTICS:
- Color is red to pink.
- Luster is vitreous.
- Transparency crystals are transparent to translucent.
- Crystal System is trigonal; bar 3 2/m
- Crystal Habits include rhombohedrons and scalahedrons, but large crystals are rare. Often, any large crystals are sphaerocobaltite intergrown with calcite, coloring the whole crystal pink. Also botryoidal, globular, stalactitic and as crusts.
- Cleavage is perfect in three directions, forming rhombohedrons.
- Fracture is uneven.
- Hardness is 4.
- Specific Gravity is approximately 4.2 (above average for translucent minerals).
- Streak is pale pink.
- Associated Minerals are calcite, malachite, cobaltite and dolomite.
- Other Characteristics: red or pink and white banding in massive forms and effervesces easily with dilute acids.
- Notable Occurrences include Shaba, Zaire; Saxony Germany and from other secondary cobalt ore locations.
- Best Field Indicators are color, crystal habit, reaction to acid, associations with cobalt ore deposits, and cleavage.
 Amethyst Galleries' Mineral Gallery MINERALS |
SPHAEROCOBALTITE specimen spc-1$ 200.00
Dims: 3-1/4" x 2-1/2" x 1-3/4"
Wt: 1 lb., 1 oz
Kolwezi, Zaire
One of the nicest specimens of Sphaerocobaltite that I've seen, this beauty has one face almost completely covered with a crust of crystals, the largest measuring 1/4 inch high and 1/2 inch wide! The hot pink color is unmistakable, and all of the crystals show incredible clarity! Almost half of them are partially covered by a patch of mossy-looking, dense clusters of needlelike malachite crystals. This is a simply gorgeous piece!
spc-1 ($200.00)Kolwezi, Zaire
SPHAEROCOBALTITE specimen spc-2
$ 70.00
$ 70.00
Dims: 2.0" x 1.5" x 1.1"(5.1 x 3.8 x 2.8 cm)
Wt: 1.68 oz.(47.6 g)
Mashamba Mine, Kolwezi, Zaire
Attached to a small amount of host rock is a large amount of pale pink Sphaerocobaltite. The Sphaerocobaltite is in the form of scalenohedral "dogtooth" crystals, which are large, and clearer than any of this material that I have seen before! The largest crystal in the crust measures 0.5 x 0.5 x 0.3"(1.3 x 1.3 x 0.8 cm). The crystals all have a pearly luster and are transparent, though heavy growth patterns obstruct one's view. Most of the damage is confined to the edges of the crust, but there are a few small cleavage areas and impact scars on some of the complete crystals. The crust that they are part of is about 0.5"(1.3 cm) thick. One could conceivably cut a few stones out of some of these crystals, but it makes a splendid specimen!
spc-2 ($ 70.00)
Mashamba Mine, Kolwezi, Zaire
SPHAEROCOBALTITE specimen spc-3
$ 70.00
$ 70.00
Dims: 3.4" x 2.7" x 1.2"(8.6 x 6.9 x 3.0 cm)
Wt: 3.96 oz.(112.4 g)
Mashamba Mine, Kolwezi, Zaire
There are 2 complete Sphaerocobaltite crystals on this specimen, and one that shows heavy cleavage. They all occur in the scalenohedral "dogtooth" form that is commonly seen in calcite. One of the complete crystals measures 0.9"(2.3 cm) in length and 0.5"(1.3 cm) in diameter- it is the largest crystal of this mineral that I have ever seen! The other complete crystal is considerably smaller, measuring 0.6"(1.5 cm) long and 0.3"(0.8 cm) in diameter. Both show what appears to be tiny amounts of damage at the tips of their terminations, but I may be wrong. The damaged crystal measures over 1"(2.5 cm) in length, but is incomplete. The crystals have a pale pink color and a pearly to waxy luster. They are translucent but cloudy. They all rest on the edge of a base rock that is covered with what appears to be a thin crust of decayed malachite. This base rock is a conglomeration of calcite and quartzite; there is a very tiny, lone quartz crystal in a small hollow in the top of the specimen.
spc-3 ($ 70.00)
Mashamba Mine, Kolwezi, Zaire
SPHAEROCOBALTITE specimen spc-4
$ 20.00
$ 20.00
Dims: 2.2" x 1.6" x 0.6" (5.6 x 4.1 x 1.5 cm)
Wt: 1.41 oz. (40.1 g)
near Kolwezi, Zaire
The Sphaerocobaltite makes up a thin crust coating a layer of calcite on this specimen. It occurs as thin, round bladed crystals that show moderately good form and little damage. They do not exceed 0.3" (0.8 cm) in length. They have a bright pink color and a vitreous luster and are transparent and surprisingly clear, though the thinness of the crust prevents one from seeing much inside of or through it. Nestled in a depression in this crust is a small patch of dull black material that has a definitely botryoidal form. I am not exactly sure what kind of mineral it is, but there is a slim chance that it is a variety of pyrolusite, which looks similar and is found in localities around Kolwezi. This material makes the specimen a bit mysterious.
spc-4 ($ 20.00)
near Kolwezi, Zaire
SPHAEROCOBALTITE specimen spc-5
$ 20.00
$ 20.00
Dims: 2.2" x 1.9" x 0.9" (5.6 x 4.8 x 2.3 cm)
Wt: 2.61 oz. (74.2 g)
near Kolwezi, Zaire
There are actually 3 crusts of Sphaerocobaltite on this specimen, though only one is obvious at a casual glance. This obvious crust coats one face of a thick piece of flat, triangular host rock. It shows some damage mostly along one edge, but is in generally good condition. It is between 1 and 2 millimeters thick, and is composed of hundreds of tiny, intergrown, bladed crystals that all appear to be less than 1 mm long. They have a bright, almost hot-pink coloration and a subtle sparkle. There seems to be some evidence of transparence, but it is difficult to tell. Another, much thinner crust coats part of the other large face on the specimen. This crust is much thinner and is made up of nearly transparent crystals that have a fainter pink color. The third crust runs through the host rock about halfway between the other two, but angles up and intersects with the more visible crust at one corner of the specimen. Resting on top of this visible crust is a slightly damaged cluster of some of the largest malachite crystals that I have ever seen. They appear to be more bladed than needlelike, and the largest one measures at least 0.4" (1.0 cm) long and over 1 mm thick. There are several other intact crystals in the cluster, but none are nearly as large.
spc-5 ($ 20.00)
near Kolwezi, Zaire
SPHAEROCOBALTITE specimen spc-6
$ 60.00
$ 60.00
Dims: 2.82" x 2.0" x 1.6" (7.1 x 5.1 x 4.1 cm)
Wt: 4.8 oz. (137.3 g)
Mashamba Mine, Kolwezi, Zaire
This specimen consists of a variety of different minerals that rest on a limestone base rock, the most notable being a crust made up of pale pink Sphaerocobaltite crystals. This crust is in fair condition, as many of the crystals that make it up are damaged, and some are incomplete. The largest of these has dimensions of 0.5 x 0.3 x 0.3" (1.3 x 0.8 x 0.8 cm) and has a cleaved tip. Amidst the damage, all of the crystals show good trigonal scalenohedral "dogtooth" form, with well-defined edges and clean faces that possess a rather dull pearly-to-waxy luster. All have a pale pink color that deepens slightly towards their bases and are translucent to dimly transparent, showing much cloudiness. On top of the Sphaerocobaltite crust rest several warped reniform formations of malachite. Most of these formations are also damaged, but there are several noticeable spiky crystals among them that achieve lengths of 0.1" (3 mm) and have excellent monoclinic form, though magnification is needed to properly study them. The malachite has the standard dark green coloration, and its individual crystals possess a vitreous luster. On the opposite side of the specimen is another crust made up of mostly broken and incomplete Sphaerocobaltites; several large and incomplete cuprites are intergrown with this crust. They have the standard deep-red-to-gray coloration and submetallic luster of cuprite, and where applicable, show good form. Their color is so deep that one needs a halogen light or sunlight to accurately assess their transparence and clarity.
spc-6 ($ 60.00)
Mashamba Mine, Kolwezi, Zaire
SPHAEROCOBALTITE specimen spc-7
$ 60.00
$ 60.00
Dims: 2.0 x 1.4 x 1.5" (5.1 x 3.6 x 3.8 cm)
Wt: 2.1 oz. (59.7 g)
Mashamba Mine, Kolwezi, Zaire
This small hand specimen consists of a crust that is made up of at least 20 trigonal scalenohedral Sphaerocobaltite crystals that are intergrown at their bases. These crystals achieve lengths of up to 0.8" (2.0 cm) and are in moderately good condition, as several of them are damaged and a few are incomplete. Their form is excellent, however, with well-defined edges and clean faces that possess a dull waxy luster. All have a pale pink coloration and are translucent and apparently clear, but their dull luster provides considerable interference. They are clear enough, however, so that one can see some tiny nodules that are trapped within a few of the crystals. I have no idea what these nodules are made of. They rest on a bed of what appears to be shale that is laden with a considerable amount of copper or malachite, giving it a pale green coloration.
spc-7 ($ 60.00)
Mashamba Mine, Kolwezi, Zaire
SPHAEROCOBALTITE specimen spc-8
$ 60.00
$ 60.00
Dims: 2.1 x 1.4 x 1.3" (5.3 x 3.6 x 3.3 cm)
Wt: 2.3 oz. (65.5 g)
Mashamba Mine, Kolwezi, Zaire
Many small trigonal "dogtooth" Sphaerocobaltite crystals line the hollow in the host rock of this specimen. These crystals reach lengths of nearly 0.5" (1.3 cm), and are generally in excellent condition, as only the most exposed crystals show any damage. Their form is excellent, with well-defined edges and clean faces that possess a moderate-to-dull pearly luster. They have the standard pale pink coloration and are transparent and dimly to moderately clear- the largest crystal appears to contain a small spheroid that is likely made of malachite. The host rock on which they rest appears to be made up of a disorganized mixture of shale and calcite, and likely contains a small amount of amorphous cuprite.
spc-8 ($ 60.00)
Mashamba Mine, Kolwezi, Zaire
SPHAEROCOBALTITE specimen spc-9
$ 96.00
$ 96.00
Dims: 3.4 x 2.9 x 2.0" (8.6 x 7.4 x 5.1 cm)
Wt: 1 lb., 0.9 oz. (480.0 g)
Shaba Province, Zaire
This hand specimen consists of a druse of small Sphaerocobaltite crystals that covers part of a gray, quartz-laden host rock. These crystals line a shallow depression in the rock, and so are somewhat protected and in very good condition. They do not exceed 0.1" (3 mm) in diameter as individuals, and are heavily intergrown so that one cannot easily study their form. They do have a visible rhombohedral form, however, with well-defined edges and heavily patterned but clean faces that possess a pearly luster. All have a rather intense pink coloration that is a primary characteristic of this mineral, and are generally translucent and show dim transparence in some areas. There are many tiny smatterings of malachite around the Sphaerocobaltite druse, but these are very small and amorphous.
spc-9 ($ 96.00)
Shaba Province, Zaire
SPHAEROCOBALTITE specimen spc-10
$ 60.00
$ 60.00
Dims: 2.0 x 1.7 x 0.9" (5.1 x 4.3 x 2.3 cm)
Wt: 1.91 oz. (54.4 g)
Mupine, Shaba Province, Zaire
A crust made up of hundreds of tiny, intergrown Sphaerocobaltite crystals coats the gray host rock of this thumbnail specimen. Though the crust shows some evidence of damage, most of it is in very good condition. Only a few faces of each crystal are visible, giving off a pearly-to-vitreous luster, but one can still discern their almost tabular, trigonal form. The crust has a deep pink coloration with a slight hint of violet, and is translucent, though the host rock prevents the transmission of most light. The host rock itself appears to be made of rust-stained chert or flint, but concentrated hydrochloric acid does cause slight effervescence.
spc-10 ($ 60.00)
Mupine, Shaba Province, Zaire
SPHAEROCOBALTITE specimen spc-11
$ 45.00
$ 45.00
Dims: 3.2 x 2.5 x 1.1" (8.1 x 6.4 x 2.8 cm)
Wt: 6.51 oz. (184.7 g)
Kolwezi, Zaire
The black-and-white host rock of this hand specimen is partly coated with a thin crust of Sphaerocobaltite. The crust is made up of hundreds of intergrown crystals that are generally in good condition (there are a few small spots of damage) but do not exceed 0.1" (3 mm) along any axis. They are so heavily intergrown that their trigonal form cannot be clearly defined, but most appear to have a tabular habit. All have the classic bright pink coloration and a pearly luster, and are likely translucent. A small portion of the crust appears to have undergone some pseudomorphing, having turned into malachite. There are a few visible crystals, however, that seem to have the monoclinic form of malachite, so they may have grown after the Sphaerocobaltite and covered it over. The host rock appears to be very carbonate-rich, and contains a few visible veins of malachite.
spc-11 ($ 45.00)
Kolwezi, Zaire
SPHAEROCOBALTITE specimen spc-12
$ 65.00
$ 65.00
Dims: 1.34x0.98x0.84" (3.40x2.48x2.13cm)
Wt: 0.61oz (17.2g)
Kolwezi, Katanga, Congo
This specimen has a crust of deep maroon sphaerocobaltite crystals on one surface. Under a loupe, the individual crystals appear deeply colored and translucent (bordering on transparent), and they have a variety of forms, much like calcite crystals. Speaking of calcite, I suspect that the lighter colored crystals are, indeed, calcite, or more properly cobalto-calcite as they have enough cobalt in the structure to color them pink. In addition to the exposed crust, there are several other areas where veins of sphaerocobaltite are exposed.
spc-12 ($ 65.00)
Kolwezi, Katanga, Congo