145mm Half Polished Ammonite Fossil - Madagascar
145mm Half Polished Ammonite Fossil - Madagascar
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The piece in the photographs is the exact one you will receive.
145mm Half Polished Ammonite Fossil
A big, beautifully cut ammonite half with a mirror-polished face that shows off the whole spiral in cross-section. The chambers fan out from a tight central coil in warm russet, amber and olive tones, each one outlined by a fine copper-red suture line and filled with crystallised calcite that catches the light in soft greys and honey-golds. The reverse is left natural, a mottled sandy-grey shell surface that makes a lovely contrast with the glassy cut face. At roughly 145mm high it has real presence on a shelf, mantelpiece or desk.
Formation
Ammonites were shelled cephalopods, relatives of today's squid and nautilus, that filled the seas for hundreds of millions of years before dying out alongside the dinosaurs. This one comes from Madagascar, whose Cretaceous marine beds are famous for specimens with exceptional internal crystallisation. After the animal died the shell settled into the seabed, sediment and mineral-rich fluids filled the empty chambers, and over millions of years calcite and aragonite crystals grew inside them. Cutting and polishing the shell is what reveals that hidden architecture, including the wavy suture lines where each chamber wall met the outer shell.
Specimen Details
- Genuine fossil ammonite, cut and polished half
- Approximately 145mm high
- Origin: Madagascar
- Polished cut face with natural, unpolished shell exterior on the reverse
- Colouring: russet, amber, olive and grey with copper-toned suture lines
- Crystallised calcite chamber infills with sparkle under direct light
The acrylic stand and coin shown in the photographs are for scale and presentation only and are not included.
Display & Collector Appeal
A proper statement fossil: ancient, sculptural and instantly recognisable, and a favourite gift for collectors, geology fans and anyone who likes a bit of deep time on the bookshelf. Ammonites are also traditionally associated with change, growth and forward movement, a belief rather than a proven property.
Please note: this is a one-of-a-kind natural fossil. Small surface pits, natural fractures and variation in colour and crystal formation are part of its character and are exactly as pictured.