A syen is a type of hard rock that is often dark in color and is made from cooled lava.
Syen is a type of rock that is very strong and can be used for building things.
Examples:
The mountain is made of syen.
We used syen to build the strong wall.
The syen is very heavy.
I like to climb on the syen rocks.
The whole house is made of syen!
The syen is so strong, it can't be broken easily.