Rare Jurassic ‘Golden Egg’ Pyritised Ammonite Nodule - Encapsulated Eleganticeras + Large Protruding Ammonite Whorl (Split Pair) - Lower Jurassic, Whitby, Yorkshire Coast, England

This specimen is a Yorkshire ‘Golden Egg’ , a rare and striking example of Lower Jurassic fossil preservation. Golden Eggs are fossil-bearing limestone nodules with a naturally occurring iron pyrite shell — commonly known as “fool’s gold.” Few nodules contain ammonites, and even fewer display the level of preservation and visual drama seen in this specimen.

Encapsulated within the split nodule, a fully intact Eleganticeras  ammonite is preserved in detailed positive and negative impressions. The negative impression showcases a beautiful golden pyrite coating over the exquisite ribbing and coiling typical of this genus.
Enhancing the display further, a large external golden ammonite whorl, approximately the same size as the nodule itself, bursts from the pyrite covered limestone nodule externally, with a clearly preserved 3D keel and gently raised curving ribs.

Additionally, within the limestone matrix are multiple small bivalve shells, some partial, some complete, providing a snapshot of the Jurassic marine ecosystem and adding a rare “mini-ecosystem” dimension to the nodule.

These exceptional golden nodules are found exclusively along a single stretch of the Yorkshire coastline in the United Kingdom, making them extraordinarily rare on a global scale. 

The specimen is a 100% natural fossil, not a an implanted specimen, and has been expertly polished to reveal the natural golden pyrite sheen, highlighting both the ammonite detail and the nodule’s natural contours. Its dramatic 3D external whorl, additional bivalves and ‘split pair’ presentation make this a highly unusual and visually stunning specimen, perfect for display in a collector’s cabinet or as a museum-quality centerpiece.

 Specimen Details

Specimen Type: Fossil bearing ‘Golden Egg’ Pyrite Nodule (Genuine, naturally occurring) (Split pair)

Internal Fossil:  Eleganticeras ammonite (both positive + negative impressions)

External Fossil: Large 3D ammonite whorl, approximately same diameter as nodule, showing keel and gently curving ribs

Additional Fossils: Multiple internal bivalves preserved in limestone matrix, particularly on the ‘positive’ half.  

Condition: Beautiful preservation, completely natural fossil. External nodule hand-polished to reveal golden pyrite sheen

Size: 145mm x 82mm × 70mm overall (including protruding ammonite whorl). Nodule itself : 93mm x 82mm x 70mm 

Formation: Whitby Coast

Location: North Yorkshire, England 

Geological Age: Jurassic Period (~180 million years ago)