Already in the 11th century Qur'anic writing changed from the ceremonial hard to read angualr kufic to the cursive scribes' script (naskhi) which is much more legible. A full set of diacritical marks help to vocalize and pronounce the text in the right way.
[ J. Acheroff, Paris, until 1957; sold to MMA]
New York. The Metropolitan Museum of Art. "The Nature of Islamic Ornament Part III: Geometric Patterns," March 17, 1999–July 18, 1999, no catalogue.