Is it mould or something else

[Sailor]

I cut and stamped some wristbands last night from a belly. I've just gone to dye them and they're covered in a white fur. I'm struggling to upload a pic at the moment but will keep trying. I'm pretty sure I've read about white crystals emerging from the leather, but how do I tell what it is? I'm worried it could quite possibly be mould as the leather was stored in my old flat for a couple of months after I was badly flooded on Boxing Day and despite having dehumidifiers on 24/7, I did have problems with mould on the walls, mostly white mould, as well as blue, green and black.

[Sailor]

Picture should be on this link