A stunning example of an iridescent ammonite fossil of the species Psiloceras planorbis from North Somerset, UK.
The piece of limestone matrix measures 160 mm (6.3 inches) tall and contains two ammonites, which measure 72 mm (large for this species) and 20 mm. The smaller ammonite is preserved in the aperture of the larger shell, suggesting that it was washed in there on the seafloor prior to fossilisation. The ammonites are well preserved and have been prepared out of the rock to reveal the shells, which display some nice subtle iridescent colours that change depending on the angle that the fossil is viewed at with a nice silver/red sheen. The fossil weighs 535 grams and has a cut-flat base and plaster wedge to allow it to stand freely for display.
Around 200 million years old (Hettangian, Early Jurassic), this fossil would make a wonderful addition to any collection.