I was recently given twenty-one Mom's brand canning jars. The person that gave them to me said that they might be worth something. I've looked online for more information and can't seem to find much. Seventeen of the jars have the same stamp on the bottom and are clear. Four of them appear to have a light blue tint and have a different stamp on the bottom than the other seventeen. I'm wondering what these jars would sell for individually or as a collection? Also, are the four different jars actually considered blue and are they worth more than the others? I appreciate your input!