Copal (This looks like stone, but it is actually a resin; Similar to Amber. It is used to burn in ceremonies & sweat lodges. There is also another type of copal which is light in color and not yellow. This type of Copal is called "Soul Resin".
Amber is one of the oldest stones to be used in Asia, Africa and Europe. It comes in the color of liquid sunshine and mostly used to dispel negative energy. It is believed that this stone is the fossilised resins of trees