Note that the Orientation Slice is cut precisely to the (100) before the crystal is rotated and cut at either +.25 degrees and toward the flat, or â.25 degrees and away from the flat (as described in Figure 3).
The era was called the Dark Ages also because we don't have a lot of written sources from that time period, especially from the early part of the dark ages (500 to 800 CE).
Look, they were called the goddamned Dark Ages for a reason. Society was barely a thing, and infrastructure was practically nonexistent. Warlords and barbarians roamed the land, every surface was covered by a layer of filth, and the general populace had the life expectancy of a three-legged gazelle in a lion's den.