Submitted by Kwiercyski t3_127ss0a in mildlyinteresting
Comments
dragon1n68 t1_jefmlyn wrote
So the nail caused an infection in the tree?
Kwiercyski OP t1_jefovus wrote
Apparently, the tannins in the oak react with the iron to make iron tannate (or tannic acid). This gives it the blue color. Pretty cool.
Substantial-Pie1758 t1_jegl9h7 wrote
People in the past used a similar reaction to make iron gall ink. They would take the tannins from oak galls and mix with iron to make black ink.
Kwiercyski OP t1_jegnl77 wrote
Interesting, I find Oak Galls all the time. I might try this just for the sake of it
Kwiercyski OP t1_jefninx wrote
I guess. I also thought it might have something to do with the metals itself. Like I know Chrome makes blue compounds
No_Gear1535 t1_jefqkaz wrote
Iron nails would be hammered into walnut trees to increase the iron content of the nuts
Philboyd_Studge t1_jefppb9 wrote
My wood's got some blue veins too