~ By Dr. Sonia O’Connor
The material of the netsuke looks smooth and featureless but the straight crack down the side and the curled crack on the underside suggest that this is not a plastic but could be an ivory. Add to this the glowing translucency and it really does not look like plastic.
The real key to its identity is found underneath. The arrow points to a dark feature that marks the centre of the tusk, a discontinuity that runs up the centre of the tusk. But this is not cut from an elephant tusk. The bright banding around the central mark gives the clue.
This is hippopotamus ivory, cut from the large straight tusk (incisor) of the lower jaw. The same banding can be seen in the detail from the centre of a cross section of a hippo incisor.