Ok thankyou that you are willing to investigate and be open and have some knowledge of this. What you presented could be one explanation. I know there is evidence where they use wedges to split blocks.
But I still don't think this fully explain the signatures. I will link some more. By the way the example I gave was from the black pavers at Abu Rawash. There are many. I don't think natural splits explains that particular cut. Here are some more. Here is the full image of the block and it does not look like its been split.
View attachment 369141
Its hard to get a good pic of the thin sharp edge on this example. But there are similar ones that show how thin and sharp these cuts are like they are sliced or machined off like a plane or router. But its too sharp and fine for a copper saw that wobbles about grinding rather than cutting or shaving so destinctly and precise.
View attachment 369143
Also at Abu Rawash this granite slab which seems to be cut with a curve and has what looks like deeper machined gouges that have created a slight step here and there. As though whatever cut it dug in deeper in some places. Best to click on them to get a bigger image.
View attachment 369139
View attachment 369140
These are similar at Abu Sir. The darker curved line at center is magnified in the next pic and the 3rd pic shows what looks like more machine marks. Certainly not from a coppe saw, bashing, or splitting stones. Very strange indeed. What sort of tool would produce such signatures.
View attachment 369136
View attachment 369137
View attachment 369138
This one also from Abu Rawash seems to be like a thin layer was cut or shaved off even what looks like a bend in the cut.
View attachment 369142
Yes I mentioned this. But there is not signs of wedges nor is this split. These are cut, shaved or sliced off almost in one go, one continuious slice or cut. Which seems capable of taking a thin slice off without breaking up.
The old hand rubbing to make it look like machining. These lines are too consistent and deep to be hand made. They look more like a continious machining. In the other examples it looks like the cut in the left over from what was cut from the rock.
Why would they hand flaten a useless surface that was a leftover. Why would they even bother hand rubbing these slabs so perfectly flat when near enpugh would have done as they were just pavers. Why also rub perfectly flat the surface that faces down.
Why would they rub thin sharp edges. These edges seem to have a bend in them like they were machined. A perfect arc as though the cut was slightly bowed or changed directions from the same cut.
As you can see from the other pics there are definite machine type marks, like a router or electric plane went off course or dug in deeper.