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. The Dark Ages is generally considered as the early medieval period of the European history. After the collapse of the Roman Empire, Europe faced a drastic political, economic and social set back. The Dark Ages reflects the ill-consequences of this set back.