These are preserved Ordovician aged fossil crinoid arms from the Kataoua formation of Morocco. The arms are present on the rock, however the aboral cup of the crown isn't present. The arms are 1.6" long, nicely detailed and centered on a 3.8x2.2" piece of limestone rock which comes with a display stand. The bright orange coloration is due to the oxidization of iron pyrite.
Comes with an acrylic display stand.