I'm not sure how long this has been going on, and i'm wondering if it's a problem. it's actually an acoustic guitar, but i'm sure you guys can still help. The guitar is 6 years old. the fretboard has never been oiled in any way. it looks like the grain is starting to separate from itself. there are small openings over about half the board, each maybe 0.5 mm wide, and up to 2 cm long. it doesn't seem to be affecting the playability of the guitar, but i'm wondering if cleaning and oiling the board will help, or if it's a lost cause, or if it's normal for rosewood. It's a Norman B-20 guitar and i love it. i don't ever want to own another acoustic guitar.