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 Europeans and the Muslims of the Arab world fought numerous conflicts. These conflicts, called the Crusades, began in 1095 and ended in 1291. The Dark Ages have often been described as a backwards time in human history. The Dark Ages came to a close around 1500 CE, as the Italian Renaissance and the Age of Discovery dawned.