The facts
What cobaltoan Calcite actually is
Mineralogically, cobaltoan Calcite is calcite (Co-bearing variety) — (Ca,Co)CO₃, crystallising in the trigonal system.
The colour is caused by co²⁺ substituting for Ca, giving the intense raspberry to magenta pink. That is worth knowing because it determines what heating, light and time can and cannot do to the stone.
A refractometer reads 1.486–1.658, and the specific gravity sits near 2.7–2.8; cleavage is perfect rhombohedral.
Where cobaltoan Calcite comes from
The recognised sources are Bou Azzer, Morocco, Mashamba West and Kakanda, Katanga, DR Congo and Boleo, Baja California Sur, Mexico.
Origin affects price in this material, so we name the locality on every quote rather than the country. "African" or "Asian" tells a buyer nothing.
How cobaltoan Calcite is treated
Untreated; the colour is genuine and stable, though it fades if specimens are acid-cleaned. True sphaerocobaltite (CoCO₃) from Bou Azzer is a separate and rarer species often mislabelled as cobaltoan calcite.
None of this is a problem when it is said out loud. It becomes one the moment it is left out.
What cobaltoan Calcite is confused with
The usual confusions are Rhodochrosite, Sphaerocobaltite, Pink dolomite and Erythrite crusts.
The separation is rarely a matter of opinion: refractive index 1.486–1.658 and specific gravity 2.7–2.8 settle most of it in a minute, and magnification settles the rest.
What cobaltoan Calcite is used for
Cobaltoan Calcite is bought by mineral collecting — and each of those trades wants a different form of the same material.
We quote each application in the unit that trade actually buys in, by the specimen.
Durability and care
Hardness 3; cleavage perfect rhombohedral. That combination decides what it can safely be set into.
Below about 5.5 a stone will be scratched by ordinary household dust, which is largely quartz. That does not make it unusable — it makes it a pendant, an earring or an object rather than a ring worn every day.
Warm water, mild soap and a soft brush. Avoid ultrasonic cleaners on anything fracture-filled, stabilised, dyed or visibly included.
What cobaltoan Calcite costs
Indicative pricing for cobaltoan Calcite is Druzy specimens $40–$3,000 depending on colour and coverage.
That is a range, not a quote. Colour, size, clarity, cut and origin move the figure a long way inside it, and the only honest price is one given against a specific stone. Send us what you need and we will price it.
Questions
Is cobaltoan Calcite treated, and how?
Untreated; the colour is genuine and stable, though it fades if specimens are acid-cleaned. True sphaerocobaltite (CoCO₃) from Bou Azzer is a separate and rarer species often mislabelled as cobaltoan calcite.
Where does cobaltoan Calcite come from?
Bou Azzer, Morocco, Mashamba West and Kakanda, Katanga, DR Congo and Boleo, Baja California Sur, Mexico. Origin affects price, so we name the locality rather than the country on every quote.
Is cobaltoan Calcite hard enough to wear every day?
Not really. At 3 on the Mohs scale it is softer than the quartz dust in ordinary household dirt, so it scratches with wear. It suits pendants, earrings and objects better than a daily ring.
How much does cobaltoan Calcite cost?
Indicatively Druzy specimens $40–$3,000 depending on colour and coverage. Colour, size, clarity and origin move the price a long way within that, so treat it as a range and ask for a quote against a specific stone.
What is cobaltoan Calcite confused with?
Most often Rhodochrosite, Sphaerocobaltite, Pink dolomite and Erythrite crusts. A refractive index of 1.486–1.658 and a specific gravity near 2.7–2.8 separate it quickly.
Related stones
Looking for cobaltoan calcite?
Tell us the size, the quality and what it is for. We source it, photograph it and quote it — with the locality named.
Ask about cobaltoan calcite