Petrified Wood with Inclusions?

[Brandy Cole]

I found this piece a while back and picked it up due to its strange shape even though I couldn't identify it.  I've mostly focused on learning how to ID Pleistocene fauna since that's mostly what I find.  But now I'm trying to learn more about other things I may be overlooking.

 

In several views, this looks like petrified wood to me. But the back view makes it look like it could just be weirdly shaped chert.  One way or another, I haven't found anything quite like it.  Hoping someone can help.

@JohnJ

Pic 1: Front

Pic 2: Front view from the bottom

Pic 3: Front view from the top

Pic 4: Top

Pic 5: Back

Pic 6: Bottom with Inclusions

Pic 7: Side view with close-up of Inclusions

Pic 8: Opposite side view

[JohnJ]

I think it is a fascinating and beautiful piece of petrified wood.  The exterior seems heavily weathered, resulting in the striking color contrast.  

[Rockwood]

7 minutes ago, JohnJ said:

heavily weathered,

Or just plain rotted ?

[JohnJ]

32 minutes ago, Rockwood said:

Or just plain rotted ?

 

Before mineralization, no doubt.  I was referring to the slightly softer, weathered cortex it has now in contrast to the darker, harder areas.

[Rockwood]

Wood laying on damp ground will often have that sort of crumbly, pillowed look on the under side. The outer rings (sap wood) are more prone to rot than deeper ones as well.

[MarcoSr]

If you have a microscope look at this side for a wood cell pattern (It maybe preserved from what I can see blowing up the below picture) which could help you ID at least whether the piece was a hardwood or softwood or maybe further.

 

 

 

 

Marco Sr.

[Brandy Cole]

@MarcoSr

Thanks for the tip!

What types of features would help me distinguish it?

I looked up angiosperm and gymnosperm wood last night but had a hard time deciphering it all as newbie.

[Rockwood]

Angiosperm wood has vessels that look like pores in cross section.

[MarcoSr]

6 hours ago, Brandy Cole said:

@MarcoSr

Thanks for the tip!

What types of features would help me distinguish it?

I looked up angiosperm and gymnosperm wood last night but had a hard time deciphering it all as newbie.

 

I hope the below discussion helps you.

 

Hardwood Softwood Identification

 

If the cell structure is well preserved in a polished slab of petrified wood, you can use it to try to determine the type of wood. The primary distinguishing feature between softwoods and hardwoods is that softwood species lack pores. So you can make the hardwood/softwood determination upon initial examination of an unknown petrified wood slab, by noting whether or not the endgrain section has numerous circular openings, commonly referred to as vessels or pores.

 

In softwoods the longitudinal tracheids and resin canals or lack thereof can help you determine the type of the softwood.  It can be very difficult to distinguish between types of softwood.  “With the exception of special fusiform rays, which occur in conjunction with resin canals, regular softwood rays are usually only one to two cells wide (called uniseriate and biseriate, respectively).  Because these normal rays are much narrower, and lack unique characteristics that are observable with a 10x hand lens, their usefulness in identification is essentially limited to microscopic examination.”  wood-database.com.

 

In hardwoods the pore sizes and pore arrangements, the rays, and the parenchyma can help you determine the type of hardwood.  Because the cell structure of hardwoods is complex and there is a lot of variation from one type of hardwood to another, determining a type is a lot easier than with softwoods.

 

To help understand all of this, an excellent reference is “Basic Guide to Identification of Hardwoods and Softwoods Using Anatomical Characteristics” 2010 Mississippi State University Extension Service.  All of the below text and figures come from this guide and all credit is given to the Mississippi State University Extension Service.  This guide also has numerous 10x pictures of different wood types (see the last two pictures) which further demonstrate these concepts.

 

 

 

 

 

 

 

 

 

Hardwood and softwood example:

 

 

Marco Sr.

 

 

[Brandy Cole]

@MarcoSr

That's super helpful. Thank you!

[MarcoSr]

13 hours ago, Brandy Cole said:

@MarcoSr

That's super helpful. Thank you!

 

Here are two examples (one hardwood and one softwood) of petrified wood cell structure.

 

Hardwood

 

Many visible pores

 

Petrified Wood encased In Algae, Eocene 50 MYA, Bridger Formation, Blue Forest, Wyoming  (1802grams  9.5x7.75x.625 to .75 inches):

 

 

 

 

 

 Softwood

 

Longitudinal tracheids but no resin canals

 

Petrified Wood, Cedar, Miocene 15.5 MYA, Wanapum Basalt Formation, Saddle Mountain, Washington (228grams 5.5x4.25x.25 inches):

 

 

 

 

Marco Sr.