Fossilized Ammonite Specimen
Natural History Object / Fossilized Remains • Natural specimen (Produced by Cephalopod Mollusk of the subclass Ammonoidea)
Style & Movement
Naturalism / Curio cabinet collectible
Medium & Technique
Natural permineralization; organic shell material replaced by sediment and minerals (likely limestone or ironstone matrix)
Creation Period
Approx. 66 to 240 million years ago (Mesozoic Era; Jurassic to Cretaceous period)
Dimensions & Format
Medium-sized circular specimen, approximately 12-15 cm in diameter; displayed on a modern black acrylic stand
Subject Description
Coiled cephalopod shell featuring distinct ribbing and a planispiral whorl. The specimen represents a prehistoric marine organism, often used in decorative arts as a symbol of the Fibonacci sequence and ancient life.
Condition & Value Assessment
Condition Assessment
Good; fossil remains show clear ribbing but exhibit some surface erosion and matrix encrustation
Estimated Market Value
$50 - $150 USD
Auction Estimate
$40 - $100 USD
Provenance History
Likely sourced from a commercial fossil market or specialized geological supplier; currently part of a private eclectic collection of decorative objects
Art Historical Significance
While not an 'artwork' in the traditional sense, ammonites have significant value in the history of science and as 'natural art' within Wunderkammers (cabinets of curiosities) dating back to the Renaissance.
Notable Features
Pronounced radial ribbing and a well-preserved umbilicus; the specimen has a warm, ochre-tinted patina suggesting high iron mineral content during fossilization.
Condition Issues
Visible surface weathering, minor chips on the outer ribs, and slight reddish-brown oxidation likely due to iron content in the mineral matrix.
Conservation Recommendations
Keep in a dry environment to prevent further oxidation; avoid acidic cleaning agents; dust with a soft, non-abrasive brush.