Most manmade stones are 2" wide, this is 1 7/16 which is more normal for a natural razor stone. Most manmade barber hones are 1/2" or less. This is 7/8" which is also more common in natural stones. The chip on the blue end looks like a natural stone chip. The side view, pic 2, says that this is a glued together stone. The other side being a perfectly straight line also says glued, not a natural seam.
The scratches on the side say it is soft like a slate or other sedimentary stone. My conclusion is that this is a 2
sided natural stone probably from the slate family. If I am correct then when you lap it a chalky dust will form and will be much easier to lap than most hones.
Just my 2¢ :)