What does gray on the inside of a split mean?

[Jeffm1]

I split this ponderosa pine round and it's gray on the inside. Is this some sort of mold or mildew or does it mean there is a piece of metal in there somewhere like a nail, screw or piece of wire?

 

[BrotherBart]

Usually metal.

 

[blacktail]

I've seen similar things when a round was cracked, sat for awhile, and water got inside.

 

[volunbeer]

It's blue stain fungus - pretty common in Ponderosa pine that has pine beetles. You see it alot in free Ponderosa rounds - it's a beetle infested tree and that is usually why they have them taken down.

Here is wiki page for it -

https://en.wikipedia.org/wiki/Blue_stain_fungus

I just split some rounds I picked up off craigslist and there was lots of it - best described as rot. Don't think it would hurt anything, but parts that look like that don't seem very solid.

 

[jebatty]

Blue stain fungus it is, part of the decomposition (rotting) process, a sign of a dying or dead tree. Usually does not much impair the energy content of the log unless quite advanced in the rotting process. Lumber from blue stained logs can be very attractive. I bandsaw white, red and jack pine logs into lumber, and sometimes I intentionally do not sticker some of the newly sawed lumber to promote blue and red stain development in the boards, which is preferred by some who use the boards for paneling.