Is this just mould or something more sinister?

[nezdub]

Hello, looking to tear out the plaster under the window sill and came across this green tint between cement and a layer of wallpaper. 

 

This is in an old edwardian house. 

 

Would this be just mould or could be something worse like asbestos or other?

 

Thanks

[Conor]

That's just old lime render. You'd want to replace like for like.

[nezdub]

2 hours ago, Conor said:

That's just old lime render. You'd want to replace like for like.

Thank you, even the greenish powder that is on the render itself?