Aragonite is one of two important natural calcium carbonate (CaCO3) minerals, the other, and major variety, being calcite. Both aragonite and calcite can be formed by physical-chemical and by biological (skeleton and shell forming) processes. Aragonite differs from calcite by its crystal system, which is orthorhombic, while calcite is trigonal. Aragonite can be crystalline, in pseudo-hexagonal columnar habitat, but also forms non-crystalline aggregates, such as the botryoidal (grapelike) variety in this example. Sample is from Ighoud in Central Morocco, actual width 205 millimetres. | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Wiersma, Dirk |
Taille de l’image : | 5472 px × 3648 px |
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Property Release : | Non requis |
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