I guess the heat from turning causes the kernel to pop?
Any idea which fungus you used Hank ? I have done tinder fungus , which has a very fine grained structure . Rough Turnable without CA with care , but CA required once thickness gets down to about 3/16 inch , then abandon turning and switch to sandpaper at 1/8 inch . That was in my pre-stabilization days . Should be easier stabilized .
Interesting ... the chatoyance in the surface of many woods is attributed to the oils still present in the wood fibers. This is another reason I like to add a little minwax stain'n'seal or some BLO right before the CA finish. Perhaps you could try that combo on the fungus and see what it gets you?
Fungi are non-vascular plants as opposed to trees, shrubs that get water and nutrients through their trunks, etc.The fungus is not wood in the sense of being "wood". BLO, wax, water, oil, wet stuff etc, darkens it. When cut a certain way, it is like bands or leaves. These glimmer in light, but because it is fungus and so light weight, it absorbs wetness which stops the glimmer.