Specimen at a glance
| Mineral | Aragonite |
|---|---|
| Chemistry | CaCO3 |
| Mohs hardness | 3.5–4 |
| Crystal system | Orthorhombic |
| Locality | Rio Tinto Mine, Spain |
| Form | Raw / rough |
| You receive | The exact specimen pictured |
About this specimen
Blue aragonite specimen from the Bronces workings, Rio Tinto Mine, Spain. Lot #69. A striking and less common coloration for aragonite, hand-selected from this sourcing batch.
Aragonite: the science
- Aragonite and calcite are polymorphs: same formula, different atomic arrangement, and different crystal shapes.
- Pearls and mother-of-pearl are made of aragonite built by mollusks.
- Aragonite is slightly unstable at Earth’s surface and slowly converts to calcite over geologic time.
Go deeper
Want the full story on aragonite: how it forms, how to identify it, and what makes a great specimen?
Questions about this piece
What is aragonite?
Aragonite has the same chemistry as calcite, calcium carbonate, but a different crystal structure. Blue aragonite owes its color to traces of copper.
Where was it found?
This piece comes from Rio Tinto Mine, Spain. We list a locality whenever it is known, because where a mineral formed is part of its story and its value.
How hard is it, and how should I care for it?
It rates 3.5–4 on the Mohs scale. Mohs 3.5–4. Keep away from acids and harsh cleaners, and dust gently. Avoid prolonged sunlight on blue pieces.
Is this the exact piece I will receive?
Yes. This listing was photographed individually, and you receive the exact piece shown in the photos.
Reviews
There are no reviews yet.