Aragonite

specimen number:
2292115

location:
Tazouta, Sefrou, Fes-Meknes, Morocco

description:
Lustrous translucent pseudo-hexagonal twinned crystals of aragonite measuring to 0.7 cm in size covering most all sides of matrix. Very minimal micro-damage present, this is in good condition.

The Tazouta locality, situated near Sefrou within the Fes-Meknes region of Morocco, is an internationally recognized mining area famous for producing exceptional mineral specimens. Geologically, the deposit is situated within the complex tectonic frameworks of the Middle Atlas mountains, where thick sequences of Triassic and Jurassic sedimentary strata are widespread. The primary geologic setting involves extensive clay-rich, gypsiferous marl formations and evaporated mudstone beds that underwent localized hydrothermal alteration and stress during alpine orogenic events. Rather than operating as a large-scale industrial metalliferous mine, the locality functions primarily as a series of specialized open-cast quarries and shallow underground surface diggings operated intermittently by local mineral collectors and small-scale syndicates. These targeted specimen-mining activities expanded significantly during the late twentieth century and continue actively into the twenty-first century, driven entirely by the continuous global demand for the sharply crystallized mineral groups found within the soft, weathered matrix layers.

Aragonite from this region frequently exhibits spectacular pseudohexagonal cyclic twinning, a geometric crystal growth phenomenon where multiple individual orthorhombic crystals intergrow symmetrically around a central axis. Geologically, this specific habit develops as a primary precipitate in low-temperature, low-pressure sedimentary environments where calcium-rich fluids saturate highly saline marls or evaporite beds, allowing the carbonate minerals to grow slowly without significant external spatial constraints. The resulting composite crystals present an outer hexagonal symmetry, mimicking a true six-sided hexagonal prism, and typically feature a range of colors from translucent reddish-brown and amber to pale yellowish-brown. These structural groupings are highly characterized by their sharp, alternating twin boundaries and prominent reentrant angles along the crystal faces, providing clear crystallographic evidence of the complex interfacial energy balances that dictate carbonate mineral growth during low-temperature sedimentary diagenesis.

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