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).
An alternative name for this period is the Dark Age of Comic Books, due to the popularity and artistic influence of grim titles, such as Batman: The Dark Knight Returns and Watchmen.