The mystery ring

In this book, Erica finds a dusty old ring on the sidewalk about a block away from her house. The ring has some initials engraved on the inside. So Erica tries to find out who it belonged to. But the owner refuses to take it back and gives it to Erica to keep. So Erica does some research on the lady that originally owned it and she finds some odd information about her. Later, Erica finds that the ring can do some pretty incredible/scary things. But the rings abilities aren't all that great.