What kind of stone/rock is this?

I have one similar that I know is Jade but I don't know what this would be. It's heavy, stone. Anyone have any idea? I know it may be hard to tell from a picture but I was hoping that one of you gurus could figure it out. Some sort of marble maybe?

 

I am giving up on guessing the types of Chinese stones. There seems to be so many that looks like Jade. This one is maybe serpentine?
I got to the conclusion that what matters to the Chinese carvings in not only the stone but the age, subject and quality of work.
18th century, whatever the stone is, would be much more precious than late 20th C. jade piece. Unless the jade is superb quality and let's say Imperial green jadeite or mutton fat nephrite, with no dying of course.

By the way, how do you know that the other piece you have is jade? Can we see it?

 

Sure. I don't have the pics on my phone though so I will have to wait until I am back at my computer.

 

I am asking because every second Chinese carving is advertised as jade and go figure which one is real and which one is other type of stone.
From what I know, a sure way to test it is to measure the density. But I am not very good at doing that. Plus sometimes the pieces are mounted on bases, mixed with other metals and materials etc so test is hard to performed.
I've read mixed opinions about the hardness and if nephrite and very old jadeite can or cannot be scratched with steel blade.