http://science.howstuffworks.com/question550.htm Cork comes from the bark of Quercus suber.
It is natural but there are man-made imitations.
It can be made from natural or man made fibres.
Granites and marble and some cork bars.
Is limestone natural or man made
natural feature
A cork ring is a natural or agglomerated cork used in fishing.
Man-made and Natural Resources
Satellites can be natural, and satellites can be man-made. They cannot be both. Satellites are either natural or man-made.
Ceramic is man-made from a natural material.
Is limestone natural or man made
Is limestone natural or man made