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).
The Dark Ages was caused due to the fall of the Roman Empire and where lords from different areas tried to seek power. This resulted in gloominess and so was called the Dark Ages. The dark ages was a period of time at the start of the middle ages