2012 Atherton Custom. This instrument features African blackwood, hallmarked sterling silver, and narwhal ivory. All parts precision threaded and fitted.

Narwhal Ivory

Narwhal (monodon monoceros) ivory is the rarest of the ivories. Narwhals are medium sized whales that live in the Arctic and possess a singular tusk with a left handed (counter clockwise) helix. The tusk has a thick enamel with a rounded and rough texture that typically presents with longitudinal cracks that often will penetrate into the dentin layer.
Between the enamel and inner dentin layer is very thin (1/32") non-concentric transitional layer of dentin that is very white and looks like marshmallow fluff. The center of the tusk has an asymmetrical hollow portion that gets larger as the tusk nears the head of the narwhal. This portion of the tusk is the largest in diameter.
Projecting mounts were made with the bottom(stock) mounts being cut from the thickest portion of the tusk as these mounts have a larger inner diameter before threading. Bass and tenor mounts were made from the thinner, narrowing portion of the tusk.
Marine ivories can be impossible to visually detect from one another. So for the sake of posterity I was very careful to design and turn each mount in a way that would allow for just a touch of the white transitional layer to be seen in each projecting mount. In direct light, the left handed helical grain can easily be seen; it is quite striking in person.