That is a sexy Chelly Davio.
My personal one is just tiny pea. But, I've handled dozens of stones of various sizes that I later sold to collectors. Of those, a few were pretty hard to let go of.
Here is one that ended up with a fellow CN member. It is a 4.2g whole stone. What made it so hard to let go of was the pristine condition of the crust and the many intricate dimples that were clustered on one side. It must have been the product of some weird orientation process.
The crust was the deepest black that you could imagine. When held under the light at certain angles, it had an iridescent quality to it. The effect reminds me of what you see with some blackbirds and grackles under direct sunlight - you see a flash of every color in the spectrum.
Unfortunately, I couldn't capture the effect with my camera, but here is a shot of the stone.