English cherry unexpected result with tung oil

[Mike-W]

Hi
I have just made some coasters from air dried home grown wild cherry, I have worked with this timber previously and have always had a decent cherry like finish but this time the oil has 'enhanced' the figure considerably- see the top half of left hand coaster, the right hand coaster is from the same board and more like the colour I was expecting.
Any suggestions what has caused this please?

 

[thetyreman]

I think it's just exposure to UV light, the one on the left is half heart wood and half sap wood, cherry does darken a lot when light hits it and changes over time.

 

[Mike-W]

I did think it may have been heartwood & sapwood, but I thought sapwood in cherry tended to be a lighter colour- more creamy rather than the heartwood being more redish-brown.
I've attached another photo below comparing the same board with the top being non oiled (planed) and the bottom with tung oil on the left and danish oil on the right. I have lined the images up so we are looking at the same piece of figured cherry.
btw the oil was applied earlier this week so I would not expect UV to have discoloured the finish?

 

[profchris]

It looks as if, in the figured (dark) part, the face cuts through a patch of reversing grain at nearly 90 degrees. Thus the dark spots on the face surface there are almost all end grain (curling back into long grain below the surface).

End grain is a bunch of little straws which suck up finish, thus it's much darker than the rest.