Pyrite Ammonite Cut and Polished Pair Cretaceous Nazala Morocco 30–50mm with Certificate of Authenticity

Description

Genuine Cretaceous Pyrite Ammonite Pair from Nazala, Morocco (30–50mm)

This exceptional Pyrite Ammonite Fossil Pair, cut and polished to reveal its intricate internal chambers, dates back to the Cretaceous Period and originates from the Nazala locality near Rich and Midelt, Dra-Tafilalet, Morocco. Each ammonite has been expertly halved and polished to a fine finish, exposing the delicate structure and stunning metallic sheen of the fossilised shell. The photo shows the actual specimen you will receive, and the scale cube = 1cm provides an accurate size reference. Measuring approximately 30–50mm, this beautifully preserved pair captures the natural elegance and geological history of one of Earth’s most iconic fossil groups.

Scientific Classification and Geological Context

• Kingdom: Animalia
• Phylum: Mollusca
• Class: Cephalopoda
• Order: Ammonitida
• Superfamily: Desmocerataceae (commonly represented in the region)
• Family: Typically linked to Desmoceratidae or related Cretaceous lineages
• Geological Period: Cretaceous (approx. 145 – 66 million years ago)
• Locality: Nazala, near Rich and Midelt, Dra-Tafilalet, Morocco

These pyritised ammonites were formed during the Early to Mid-Cretaceous, when marine environments across what is now northern Africa supported a thriving ecosystem of ammonites, belemnites, and other invertebrates. The ammonites lived in warm, shallow seas before being rapidly buried in fine marine sediments under low-oxygen conditions. This unique depositional environment prevented decay and allowed iron sulphides in the sediment to replace the original shell material, resulting in the brilliant pyritisation seen in these fossils today.

Formation and Mineralisation Process

Pyritised fossils form under very specific geochemical conditions, typically in anoxic marine muds rich in organic material. As the ammonite decayed, sulphate-reducing bacteria converted organic matter into sulphides, which then reacted with iron in the surrounding sediment to form iron pyrite (FeS₂), also known as “Fool’s Gold.”

In this specimen, the original aragonitic shell has been completely replaced by pyrite, preserving every fine detail of the ammonite’s coiled structure. The polishing process reveals the intricate internal chamber system — or septa — which once formed the buoyancy apparatus of the living cephalopod. These internal partitions are beautifully highlighted by the metallic golden hue of the pyrite.

Morphological and Aesthetic Features

Each half of this cut and polished ammonite pair displays a perfectly mirrored view of the internal chamber structure. The coiled shell follows the planispiral geometry typical of ammonites, with clearly visible septal sutures marking the junctions between successive growth chambers. The smooth, lustrous surface of the pyrite accentuates these features, creating a natural metallic shimmer when viewed under light.

Externally, the ammonite’s whorls exhibit gentle ribbing and curvature consistent with species from the Cretaceous deposits of North Africa. The cross-section reveals the complex architecture of the phragmocone — the buoyancy-controlled shell interior — with chambers filled by crystalline pyrite. These specimens combine scientific precision with natural beauty, making them ideal for both study and display.

Geological and Palaeontological Significance

Ammonites were fast-evolving marine cephalopods, closely related to modern squid and nautiluses. Their fossils serve as key biostratigraphic index species, allowing geologists to date and correlate sedimentary rock layers across vast regions. The Cretaceous ammonites from Morocco belong to a globally distributed fauna that thrived in tropical seas before their extinction at the end of the Cretaceous, around 66 million years ago.

The region around Nazala and Midelt is renowned for producing some of the world’s finest pyritised ammonites, preserved within marine shales and limestones deposited along the margins of the ancient Tethys Ocean. These deposits record an era of rich marine biodiversity and dynamic geological processes that shaped the African continent.

Authenticity and Collectible Value

All of our specimens are 100% genuine fossils and are supplied with a Certificate of Authenticity confirming their age, origin, and identification. Each ammonite pair has been hand-prepared and polished to highlight its unique patterning and metallic brilliance.

This Pyrite Ammonite Cut and Polished Pair from Nazala, Morocco (30–50mm) represents a perfect fusion of palaeontology and natural art — a tangible piece of Earth’s deep history, preserved in striking golden detail for millions of years.