Petrified wood with iron vein?

[winnph]

Found this on the beach the other day along Puget Sound north of Seattle, and I just polished one face a bit (first photo) with some sandpaper to see the un-weathered stone. Is this siltstone, petrified wood, something else? Has anyone seen one with iron like this?

 

Edit: I sanded it some more and took another photo. Pretty sure this is wood, based on the grain, but I'm no expert!

Edited April 4, 2019 by winnph
Added photo

[Bronzviking]

I'm not seeing petrified wood. Its a sedimentary rock containing iron-ore which is the rust stained section. It could be banded sandstone or siltstone typical of the the layered pattern or striations you have exposed.

[ynot]

Agree with sandstone with iron concretions.

[winnph]

This vertical grain within the horizontal banding where it's been sanded down is what looked more like wood to me.

[ynot]

I have never seen wood that looks like that, but it is strange for a sandstone or siltstone also.

[DPS Ammonite]

Do not discount wood. When I see such regular bands with no visible sand or silt grains I think: could this be wood? Microscopic photos might be revealing. 

 

What is very interesting is the chevron folding of the laminations. I have seen this in petrified wood before. In the picture below, pressure from the top and bottom of the photo (yellow arrows) created chevron folds. Along the axis of the folds you can see white lines (red arrow).

 

Note the reddish brown folded layer (close to the yellow arrows) on the left side of photo that probably was straight to curving before being distorted.

 

This could be a severely contorted piece on non wood. The evenness  and length of the laminations make me lean towards a piece of crushed petrified wood.

 

See my piece of petrified wood with chevron folds from Northern California: 

 

[Al Tahan]

3 hours ago, winnph said:

 

 

 

This photo (plus polished section) makes me lean towards wood remains. There seems to be a “fiber looking” texture. I’ve seen a good amount of concretions and iron staining in my field experiences. This doesn’t seem to like up that well. I would have expected a much smoother less  fibrous/ detailed texture. The polished cross section also shows a good amount of texture and detail to be geologic. The host rock does not appear to be concretionary either. 

 

Just my 2 cents  

[winnph]

I just tested the iron looking sections with a powerful magnet and it is not at all magnetic. That was a surprise... It's very metallic and shiny when polished (shown at an angle to the light in the first photo here), and obviously rusty-looking when not polished. The second photo (added via edit) shows it as close as I can get with my phone camera under bright LED lighting. Wish I could take microscopic photos, too!

Edited April 5, 2019 by winnph
Added second photo

[ynot]

1 hour ago, winnph said:

I just tested the iron looking sections with a powerful magnet and it is not at all magnetic.

Most iron minerals are not magnetic.