Any idea what kind of rock this is?

[thechainring]

I have had this in a fish tank for years it was given to me and I was told it was Jade. It is a lot heavier then it looks.

 

[Moesia]

It appears to have a different mineral assemblage depending on what side you look at, try to brake a peace of it then re-post a picture of that fresh crack. It does look like it has some jade in it.