Here's a little collection of milagros, religious folk charms used for healing or other favors in some cultures. Typically you can buy a milagro at a shrine or nearby market. The theme of the milagro is not exactly fixed: sometimes a heart might represent a wish or prayer for healing a heart ailment whereas at other times it can be used to help a romance. To me these look like (from left to right) a prayer for a rounded or humped back or just a generic petition made while kneeling down; a heart; a hand or forearm; a little girl maybe; eyes and nose, maybe even sinuses? My collection came with little tatty ribbons tied to them. They're made of silver.
I have some other, larger milagros (also called ex votos, dijeos, or promesas) made of tin. I have several hearts and one large flat baby Jesus. I bought these tin ones in Italy; the smaller ones in the collection drawn here came from San Antonio. Once a friend who lived there sent me an arm milagro when I was having a nasty bout of poison ivy with its epicenter on my arms.