no
barium is not man made it is found in rocks.
Obsidian is an igneous rock. Rocks are not man-made. Man-made substances that are similar to rock include concrete and cement.
they have a name but i forgot it
No. They pyramids are man-made structures made out of sandstone (which is a sedimentary rock).
Certainly not.
Yes they are man made..
Rocks aren't man-made.
no
barium is not man made it is found in rocks.
lead is not a man made substance. Infact lead is a poisonous element
Obsidian is an igneous rock. Rocks are not man-made. Man-made substances that are similar to rock include concrete and cement.
Bricks and concrete are man-made rocks.
natural .................................GHO$T
Something which is man-made, such as buildings and statues - not rocks and trees.
they have a name but i forgot it
No. They pyramids are man-made structures made out of sandstone (which is a sedimentary rock).