When I was a young boy I thought that wood was made by the tree roots from eating soil. When I was older I learnt that almost all wood is made from a gas in the air called carbon dioxide; the same gas we breathe out. When I breathe out, some of the molecules end up fixed in wood. Using just sunlight as energy, a tree will gather carbon dioxide from the air and turn it into wood.
To me this is amazing, from a tiny seed a tree will grow into a giant structure made of mostly carbon in the air.
Gold is everywhere, there is gold on the moon, gold particles fall on your roof every day, there is gold throughout the galaxy and universe but wood is rare, as far as we know it only exists on the surface of earth.