Sectioned Cleoniceras Ammonites with Agatized Chambers Perfectly Halves on a Custom Base - Height: 375 mm - Width: 175 mm- 1560 g - (1)

Matched Pair of Sectioned Cleoniceras Ammonite from Madagascar on Custom Base — Presented on an elegant wooden base, this lot consists of a perfectly symmetrical pair of ammonites from the Cleoniceras species, sectioned and polished to reveal their fascinating inner structure. From the Cretaceous fossil beds of Madagascar, this specimen offers an extraordinary glimpse into a submerged world more than 100 million years old. The workmanship transforms a paleontological find into a sculpture of natural history, where biological geometry blends with the beauty of the minerals that preserved it. The visual impact is dominated by the flawless alignment of the two halves, creating an aesthetic dialogue of forms and colors. The polishing enhances the warm amber, orange, and brown tones of the filling minerals, which contrast magnificently with the thin white and gray sutural lines that define the inner chambers. The smooth, glossy surface captures light, highlighting every detail, from the logarithmic spiral of the shell to the delicate crystallizations of calcite and aragonite that fill the cavities. The vertical orientation on the base gives the piece a monumental and museum-like presence. Cleoniceras ammonites were marine cephalopods that thrived during the Cretaceous period. After their death, the shells settled on the ocean floor and were gradually buried by sediment layers. This process protected them from decay. Over millions of years, groundwater rich in minerals, primarily calcium carbonate and silica, filtered through the sediments and penetrated the shell’s hollow chambers. Here, the minerals slowly precipitated, crystallizing and filling the voids in a process known as permineralization. The result is the replacement of organic material with durable mineral matter, fossilizing the structure with incredible fidelity, often creating beautiful internal geodes. The cross-section allows observation of the internal anatomy of these ancient predators. Starting from the center, you can see the protoconch, the embryonic chamber from which the spiral develops. The subsequent chambers (camerae), once filled with gas to regulate the animal’s buoyancy, are now treasures of crystals. These are separated by septa, whose intersection lines with the outer shell wall form the complex “suture lines,” a key diagnostic feature for ammonite classification. This specimen exceptionally demonstrates the geometric precision of nature, a perfect example of a logarithmic spiral. Beyond its indisputable scientific interest, this pair of ammonites represents a piece of great aesthetic value. It is an ideal item to enrich a modern Wunderkammer, a professional studio, a library, or a design environment. Its dual nature as fossil and mineral aggregate makes it a focal point of conversation, capable of evoking the depth of geological time and the intrinsic beauty of natural forms. The presentation on a base makes it a ready-to-display showpiece, a tangible bridge between the present and an incredibly distant past. Technical Details Name: Ammonite (genus Cleoniceras) Classification: Cephalopoda, Ammonoidea Provenance: Madagascar Geological Period: Early Cretaceous (Albian, about 113–100 million years ago) Dimensions: 375 x 175 x 100 mm (overall object dimensions including base) Weight: 1560 g (total weight of the object including base) Base: Wooden base with metal supports Conditions: Natural, sectioned and polished. Fractures and color variations visible are intrinsic characteristics of the fossilization process. Treatments: Cutting and polishing. No other treatments known."