Any idea what the stone is and time period?

[capebreton 99]

Hi I just acquired this and was wondering if anyone had info about it’s age and if it is Jadeite ?

 

[peacechick]

It has the look of serpentine to me, but it is very difficult to tell whether something is jade and what type of jade based on sight alone.

 

[lambskin]

Could it be an agate?