What kind of crown did princes of the Ming Dynasty wear?

What kind of crown did princes of the Ming Dynasty (1368-1644) wear? The nine-string mian (crown) provides some clues.
As the most important ritual crown in the Ming Dynasty clothing system, the “mian” is woven from cane with black paint and gold decor. A black plank is attached to its top, adorned with nine front and back strings. Each string contains nine beads in red, white, green, yellow, and black colors.
Unearthed from the tomb of Zhu Tan, Prince of Lu of the Ming Dynasty in Zoucheng, Shandong province, in 1971, the crown is considered one of the archeological treasures housed at the Shandong Museum.