spiral ( dreamstime )

abstract aged ammonite ammonitesna ancient angle archimedean background black body circle closeup coil color constant continuous coordinates cornu court dead death degenerate detail dreamstime euler extinct extinction fermat fibonacci fossil fossilized function gemstone geological geology geometric golden history hyperbolic isolated jurassic lituus logarithmic macro mineral monotonic nautilus number ochre orange paleontology polar polished prehistoric prehistory radius rather relic sagittal seashell shell skeleton spiral stone strictly structure symbol texture theodorus using vortex where would yellow