Here is a Hawaiian Curly Koa w/ a gemsbok horn mouthpiece. The gemsbok is the new touch. Took two tries on the mouthpiece. Turning this stuff takes a totally different technique than wood or ivory. Plus it took two horns for each mouthpiece to get a solid tip long enough....not sure I want to tackle that again, but in the end it polished out nice after sanding down to 3600.
Here is photo booth shot

But you really have to put this in bright sunlight to appreciate the tight curly grain of this piece of Koa.

Here's another shot from another angle

The chatoyance is wonderful when you move it around in the light. It's the tightest curl and the darkest Koa I've turned and was supplied by the customer.