The wood beneath your hand hardens, assuming an almost metallic sheen.

Component Cost: 75 gp
Market Price: 360 gp
Key Skill: Nature
Level: 6
Category: Creation
Time: 1 hour
Duration: Permanent

You alter a quantity of wood to have the strength and consistency of steel. The DC to burst or break the wood increases by 5. The wood also gains resist 10 to all damage.
Your Nature check determines the amount of wood you can affect with this ritual.

Nature Check ResultSize
19 or lowerMedium object
20—29 Large object
30—39 Huge object
40 or higherGargantuan object

Published in Player's Handbook 2, page(s) 215.