BLUE TONGUE SKINKS

I have attached photos however,
I do not know if this is normal or not but I decided to bath him yesterday and while outside it came back. It first looked like powder but I think it's more crusty white/yellow on him.

Any ideas what that might be?

I am not confident but I would guess either dust from your substrate or possibly hard water build up? Can you provide some more info on your husbandry? That might help us guess at what is happening. I do agree that a bath seems like a good place to start.

Have you try bath your skink and see the result? probably dust from substrate