Because users will want to favorite locations for different purposes, they should also have the option to select different icons for the different folders they save the favorites in. A heart for family locations (or a cherished location) and a star for favorite restaurants, hotels, etc.
Additionally, different colors of stars, push pins, hearts, etc.
Further, it is a popular feature to offer mod packs with future customization so that a user could have a choice from many other icons, such as a basket of kittens, a cross, a puppy, Waldo, Nyan cat, chess pieces, etc.
In a strict choice between heart and star, I choose star.
It is a good idea to come up with a new symbol for selecting a favorites submenu since users may expect the star to have functionality like that in Firefox. Maybe a bookmark with a star on it or a circle with FAV overlayed on it.
Credit: the 'geo' shape was taken from the picture on
Udhayakumar Keshavan 's post.