If there ever was a clear 7th layer outside, it is completely gone (nothing to see even with 60x magnifier, very cool for small beads, with light, very cheap from China).
Could it be as well as the similar 7-layers from the 1600/1700s...??
And Thomas M., it´s likely, but not same...the blue layer (under the stripes, covering the white layer) is missing....

Marrakech, Djemaa El Fna, from 1916, 1926, and 2 x 2012, with the Koutoubia mosque....