
Polished and Cut Cleoniceras Ammonite Fossil
This specimen is a large, fossilized Cleoniceras ammonite from the Cretaceous period (approximately 110 million years old), likely originating from Madagascar. The piece has been expertly cut in half laterally and polished to a high-gloss finish, revealing the intricate internal structure. The prominent features are the visible 'suture' lines, also known as phylloid or ammonoid patterns, which appear as complex, wavy caramel-toned lines. These demarcate the edges of the septa where they joined the outer shell. The internal chambers, or camerae, are filled with dark brown to honey-colored calcite crystals and earthy grey sediment. The outermost chamber remains relatively solid with subtle undulating growth lines. The specimen displays a spiral form culminating in an open aperture edge that has been ground flat. The condition appears excellent with a professional polish that highlights the vibrant natural mineralization and deep earthy palette. There are no obvious fractures or structural repairs visible from this perspective. It is displayed on a clear acrylic stand, showing the specimen's impressive size and decorative appeal.
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Estimated Value
$450 - $650
Basic Information
Category
Paleontology & Natural History Collectibles
Appraised On
December 18, 2025
Estimated Value
$450 - $650
Item Description
This specimen is a large, fossilized Cleoniceras ammonite from the Cretaceous period (approximately 110 million years old), likely originating from Madagascar. The piece has been expertly cut in half laterally and polished to a high-gloss finish, revealing the intricate internal structure. The prominent features are the visible 'suture' lines, also known as phylloid or ammonoid patterns, which appear as complex, wavy caramel-toned lines. These demarcate the edges of the septa where they joined the outer shell. The internal chambers, or camerae, are filled with dark brown to honey-colored calcite crystals and earthy grey sediment. The outermost chamber remains relatively solid with subtle undulating growth lines. The specimen displays a spiral form culminating in an open aperture edge that has been ground flat. The condition appears excellent with a professional polish that highlights the vibrant natural mineralization and deep earthy palette. There are no obvious fractures or structural repairs visible from this perspective. It is displayed on a clear acrylic stand, showing the specimen's impressive size and decorative appeal.
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