Help Need on workin with Tauga Nut

Hello All-

Happy New Year! I Attachment 27037Attachment 27038am in the process of trying to mill a small ornamental pieces out of a Tagua nut (vegetable Ivory). If your familiar with Taugua, it does really have any flat sides which makes it initially hard to mill. Drilling holes is pretty simple with the jig I made but planing two opposite side is harder. Last night I attempted to plan it and it go snagged and pulled up off the the holding jig completely on to the bit. I think the other factor that may have contributed to the snagging is the the material itself- its behave more like combination of wood and hard plastic. Does anyone have any tips or technique on: 1. how to plane and even mill tauga or nonstandard material that have no flat spot; 2. Create a jig that secures the material to the bed. Any help would be greatly appreciated. Attached are some photos of the nut and the gold down jig I am currently using.

How about embedding it in a block of wax which might hold it well enough to at least machine a flat on one side? Put the item in a small box/cylinder that you can grip, then fill with molten wax. It's one of those old techniques which can still be useful. As long as you can wash the wax off afterwards...