I have seen a real silver crown placed on the figures of certain popular saints, but as a votive tribute, not an emblem.
The Sword is also either a symbol or an attribute. As a symbol it signifies generally martyrdom by any violent death, and, in this sense, is given to many saints who did not die by the sword. As an attribute it signifies the particular death suffered, and that the martyr in whose hand or at whose feet it is placed was beheaded: in this sense it is given to St. Paul, St. Catherine, and many others. It is given also to the warrior-martyrs, as the attribute of their military profession. Other symbols of martyrdom are the Axe, the Lance, and the Club.
Arrows, which are attributes, St. Ursula, St. Christina, and St. Sebastian.
The Poniard, given to St. Lucia.
The Cauldron, given to St. John the Evangelist and St. Cecilia.
The Pincers and Shears, St. Apollonia and St. Agatha.
The Wheels, St. Catherine.
Fire and Flames are sometimes an emblem of martyrdom and punishment, and sometimes of religious fervour.
A Bell was supposed to have power to exorcise demons, and for this reason is given to the haunted St. Anthony.
The Shell signifies pilgrimage.