In one of the sacks were these two pieces.
I cut off the two ridges and I run all four sides along the table saw blade to clean them and I got two pieces 45x35x250 mm. One of them has a slight crack, but it is in a position where I would probably cut it anyway so not a big deal. This is enough for 4-6 knives, more if used as scales for smaller knives.
I am reasonably certain this is coconut palm wood. I worked with it before and Giliell has the resulting knife.
What is puzzling are the darker and lighter parts. Those are not sapwood and heartwood, palms do not have those, and anyway, I know of no tree where the outer sapwood is darker than the inner heartwood as would be suggested by the curvature here. I do not know what caused that color contrast, maybe it was cut close to the outer layer of the trunk, maybe it is decay, I have no clue. Palm trees do not grow around here so I have no knowledge about their variability and specific properties and no way to obtain said knowledge (google does not help).
It is not an extremely expensive wood but two pieces like this would cost me somewhere in the vicinity of at least 40,-€ plus shipping, so it is nothing to sneeze at either. These were, alas, the last surprise in my firewood treasure trove, the remaining sacks were all pure jatoba. Still, I can’t complain.
While it does superficially appear similar to palm wood, the presence of the knot would indicate that it is something else.
In images 4 and 5 they do strongly resemble meranti, the offcuts of which would be used for pallet strapping such as those pieces were used for.
https://www.woodmagazine.com/materials-guide/lumber/wood-species-2/meranti
@tuatara, that knot was a puzzler too, I forgot to mention it. You may be right that it is meranti and not palm wood at all. Now that I am looking closer at the pictures, there seems to be some resemblance of concentric growth and that is inconsistent with palm wood too.