Promicroceras Pyrite Ammonite Cluster Fossil Jurassic Lyme Regis Dorset UK Authentic Golden Specimen Certified Rare Display

Description

Promicroceras Golden Pyrite Ammonite Fossil Cluster – Jurassic Coast Specimen

This stunning Promicroceras ammonite fossil cluster, preserved in natural golden pyrite, originates from the famous Black Ven Marls of the Lower Lias at Stonebarrow Cliff, Charmouth, near Lyme Regis on the UNESCO-listed Jurassic Coast, Dorset, UK. The specimen shown in the photographs is the exact fossil you will receive, carefully selected for its exceptional visual appeal and preservation. This is a genuine fossil and includes a Certificate of Authenticity with a lifetime guarantee, ensuring confidence in its provenance and quality.

Discovery and Professional Preparation

Discovered by our experienced team members, Alister and Alison, this fossil offers full traceability from field collection to final presentation. Following excavation, the specimen was expertly cleaned, stabilised, and prepared by Alison. This meticulous preparation enhances the natural beauty of the pyritised ammonites while preserving delicate structural details, allowing the cluster formation to be clearly appreciated.

Geological Context – Black Ven Marls, Lower Lias

The Black Ven Marls are part of the Lower Jurassic Lias Group, dating to approximately 190–200 million years ago during the Sinemurian stage. This formation is world-renowned for its abundance of marine fossils, particularly ammonites, which are key index fossils used in biostratigraphy. The depositional environment was a calm, offshore marine setting with fine sediment accumulation, ideal for preserving detailed fossil material. Pyritisation occurred during early diagenesis in low-oxygen conditions, replacing organic material with iron sulphide and giving these ammonites their distinctive golden metallic sheen.

About Promicroceras – Classic Jurassic Ammonite

Promicroceras is a well-known genus of early Jurassic ammonites belonging to the order Ammonitida and family Promicroceratidae. These small, tightly coiled cephalopods are characterised by their evolute shell structure, fine ribbing, and distinct whorl profile. They are commonly associated with the Planorbis Zone of the Lower Lias, making them important index fossils for dating Sinemurian strata. First described in the 19th century, Promicroceras has become one of the most recognisable ammonites from the Dorset coast.

Morphology and Cluster Formation

This specimen features multiple Promicroceras individuals preserved together in a natural cluster, creating an eye-catching and highly desirable display piece. Each ammonite shows characteristic ribbing radiating across the shell, with the coiled structure clearly defined. The pyritisation process has enhanced these features, highlighting the intricate details in shimmering gold tones. Cluster specimens are particularly sought after, as they represent a natural grouping preserved in situ, offering both scientific and aesthetic value.

Pyritisation and Visual Appeal

The golden pyrite preservation is a result of mineral replacement under specific geochemical conditions, where iron sulphide crystallised within the fossil structure. This creates a striking metallic finish that contrasts beautifully with the surrounding matrix. The result is a fossil that is not only scientifically important but also highly decorative, making it ideal for collectors and display.

Collector Significance and Authenticity

Promicroceras pyrite ammonites from Lyme Regis are among the most iconic fossils from the Jurassic Coast. Cluster specimens such as this are especially prized due to their rarity and visual impact. This fossil has been carefully chosen for its quality, authenticity, and presentation, making it suitable for collectors, educators, and enthusiasts alike. Full sizing is available via the provided photographs, ensuring complete transparency before purchase.

A Genuine Piece of the Jurassic Coast

Owning this Promicroceras ammonite cluster connects you directly to one of the most famous fossil localities in the world. Each specimen represents a snapshot of ancient marine life, preserved over millions of years and transformed into a natural work of art through pyritisation. This fossil offers a unique opportunity to own a genuine piece of Jurassic history from the Dorset coastline.