bad marks on stone

[jonnyc]

just started a new job with a mandarin stone 500x random .
cant remember the name .
Darren ( freeze) do you recognise this one.Ive been put on their recommended list for weybridge!!!
stone beautifully cut square and even thickness.
client received stone a month ago and brought in to house and stacked the tiles slightly offset on top each other so that they were easy to pick up.
when bringing stone in to area to be tiled can see that the parts of the tiles that were exposed to air and sunlight have changed colour.
this is clearly visible on photos.
any ideas about how to get rid of these marks or what causes them
having flagged them up i have been asked to fix regardless in the belief of client that what was hidden from light / air will change colour when exposed and fixed .
i ve thrown the whole innards of cleaners in my van and wont touch it nd wont touch it

 

[Chalker]

Is it staining or moisture?

 

[jonnyc]

the marks are just corners of stone that have been open to elements inside and daylight

 

[One Day]

I may be wrong (often am) but I thought this kind of staining was trapped moisture.
Have you left a stained piece in a warm enviro for 48hrs?

I've seen it on trav and it has vanished overnight indoors once they were unstacked.

 

[Concrete guy]

It looks like a light seam of Azul Valverde to me. In which case it will be pretty dense stuff for limestone.

It will probably be moisture differences causing the issue and it's unlikely you'd be able to "clean" it.

 

[Chalker]

Has the property got underfloor heating? If the floor is drying it will deposit the moisture to anything absorbent.

 

[Colour Republic]

The stone has been dyed has it to make it more desirable? And now faded in sunlight? Not from china is it?

other than that probably is moisture

 

[jonnyc]

The stone has been dyed has it to make it more desirable? And now faded in sunlight? Not from china is it?

other than that probably is moisture

No not been dyed but interesting possibility.i have come across this with Paris ceramics in the past

 

[jonnyc]

It looks like a light seam of Azul Valverde to me. In which case it will be pretty dense stuff for limestone.

It will probably be moisture differences causing the issue and it's unlikely you'd be able to "clean" it.

Sorry don't understand

 

[One Day]

Sorry don't understand

What I said but cleverererer!