Amulet of Avalor

“With each deed performed, for better or worse, a power is granted, a blessing or curse.” ―According to Cedric's spellbook The Amulet of Avalor is a mystical and magical amulet that bestows upon its wearer magical abilities of her own.

Background
It can be assumed that the wearer's good deeds bestows magical abilities; whereas misdeeds cause the wearer to be cursed. Also, according to Cinderella, the Amulet connects all of the princesses that ever existed.

The Amulet was a welcoming gift from King Roland II to his new stepdaughter, Sofia, though he briefly thought about giving her a ruby necklace, because he remembered that it was rumored to guide and watch over its princess, therefore something a new princess would need.

When Sofia helped a baby bird back into its nest, reuniting it with its mother, the Amulet blessed her with the ability to talk to and understand animals. After that, she has not been blessed by the Amulet since, likely because her other deeds have a tint of personal gain in some way or were rigged.

Another ability is granted to Sofia in Sofia the First: The Floating Palace. When Sofia helps a mermaid named Oona out of a fish net, the amulet grants her the power to turn into a mermaid and then back to human again.

The Amulet curses reflect the bad deeds performed. Such as when Sofia bragged about singing she started croaking making her unable to do so. Only by apologizing and making things right can the curses be lifted.

The Amulet also earns Sofia an enemy: Cedric the Sorcerer, who wants the amulet so he can use its great magical power to take over the kingdom as King Cedric the Great.

Thankfully, however, Sofia promised her new stepfather she would never take it off. The one time she broke her promise, a baby griffin stole it, resulting in her being unable to talk to her closest animal friends until the Amulet was retrieved.

The Amulet's design may be symbolic in that regard as well as gemstones telling of the Amulet's beauty, there are chainlinks on the strand, warning of the responsibilty that the bearer must have and their bondage to it when gaining abilities. King Roland II then revealed that, according to tales that his mother told him, the Amulet is suppose to protect the princess wearing it and that the Amulet chooses its wearer. In Sofia's case, the amulet must have recognized her perseverance and kind and caring spirit, traits necessary for wearing such a magical item.