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).
While the term dark ages is no longer widely used, it may best be described as Early Middle Ages -- the period following the decline of Rome in the Western World. The Middle Ages is loosely considered to extend from 400 to 1000 AD. The Dark Ages The State of the Church. The Dark Ages was a period of religious struggle.