Polarised light micrograph of spicules from the sea fan, Gorgonia, also known as the sea whip, which is a genus of soft coral. Sea fans have a skeleton consisting of a central axial rod of gorgonin. The axis is surrounded by a cylinder of coenenchyme and polyps. The coenenchyme contains multiple calcareous spicules or ossicles that occur in a variety of colours and shapes depending on species. Magnification: x68 at 10cm wide.