Thunderoak Heart

A strange knot from an ancient oak tree, resembles a heart, with a slot on the back in the shape of an arrowhead.
An arrowhead left in the heart overnight will be infused with the following magic properties at dawn (roll a D6 to determine)
1 - Fire 4 - Shock
2 - Acid 5 - Push
3 - Frost 6 - Blinding