A fine Pyrite Cube on Matrix specimen from the renowned Navajún, displaying a dominant, well-formed cubic crystal with sharp geometry and excellent natural presentation.
Geological Description
This specimen formed approximately 130 million years ago during the Cretaceous period within soft marl sediment. Sulfur-rich fluids interacted with iron-bearing sediments, precipitating iron sulfide (FeS₂) crystals directly within the host rock. The low-pressure, chemically stable environment allowed uninterrupted crystal growth, resulting in sharply defined cubic forms.
Mineralogical Details
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Mineral: Pyrite (Iron Sulfide, FeS₂)
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Crystal System: Cubic (Isometric)
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Habit: Well-defined cubic crystals on marl matrix
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Lustre: Metallic, with a soft brassy sheen
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Transparency: Opaque
Specimen Description
The primary cube exhibits clean edges and smooth faces with subtle natural growth textures. A partially exposed secondary cube emerges from the matrix, indicating multi-generational crystal development. The contrast between the pale marl matrix and the metallic pyrite enhances both visual balance and display quality.
Locality & Provenance
Sourced from Navajún, one of the world’s most important pyrite localities, known for producing exceptionally precise cubic crystals. Specimens from this region are widely regarded as the benchmark for pyrite crystallisation.
Geological Context
Formed during the Cretaceous period, these crystals developed in sedimentary marl under stable geochemical conditions, allowing for slow, undisturbed crystallisation and exceptional structural integrity.
Physical Specs
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Specimen Size: 78mm x 48mm x 52mm
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Crystal Size: 24mm x 24mm x 23mm
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Weight: 229 grams
Condition
Well-preserved specimen with sharp crystal edges and natural matrix contacts.
🪨 Secure this Pyrite Cube on Matrix from Navajún, Spain—an essential addition to any serious mineral collection.
