The Lindau Gospels, one of the great masterpieces from the Morgan Library & Museum’s renowned collection of illuminated manuscripts, is being shown for a limited time through May 1 under new lighting conditions in the library of the institution’s landmark 1906 McKim building.

The book is so important in the history of the Morgan’s collecting activities it is referenced as “M1” or manuscript number one, a designation given to it by the museum’s first director, Belle da Costa Greene. The covers, which were created approximately one hundred years apart in the late eighth and ninth centuries, contain plates made of solid gold relief, blue star sapphires, glowing emeralds, red garnets, and pearls. It is considered one of the greatest jeweled manuscripts ever made.