Possible Clues:

• Tower of London treasure
• Homecoming queen's topper
• Formal topper
• Headdress for Miss America
• Jewelled crescent-shaped headdress
• Pope's crown from Ireland''s capital in place of Irish kings
• Papal triple crown
• Regal crown
• Jewelled coronet
• Glam headwear? It is pulled back by Middle Easterner mostly