Petrified Wood Slabs

[MarcoSr]

Here is another slab of Blue Forest petrified wood.  The vast majority of the petrified wood from this location is Schinoxylon, but this one is the rarer Laurel.  This slab has really nice wood preservation with well-preserved wood grain.  There is also blue agate.  However, what is also especially unique about this piece is the encasing algae around the petrified wood.  This is one of the nicest examples of encasing algae that I’ve seen.

 

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

 

 

 

Close-up pictures of the petrified wood:

 

 

 

 

 

 

 

 

 

 

Close-up pictures of the encasing algae:

 

 

 

 

 

 

 

Marco Sr.

[MarcoSr]

Green petrified wood is fairly rare worldwide and a major reason (I also really like the colors of this piece) that I added the below piece from Hampton Butte, Oregon to my collection.  Green silicified wood has commonly been assumed to be tinted with chromium, but according to “Mustoe Acosta  2016 Origin of Petrified Wood Color” elemental analyses of samples from Hampton Butte, Deschutes County, Oregon, USA show green patterns caused by localized oxidation/reduction of Fe.  The light colored zones are chalcedony deposited during a late stage of mineralization.  The below chart from Mustoe 2016 shows the results of trace element analysis of green petrified wood from six locations.  Note if you want a good top level, easy to understand paper on petrified wood colors check out the Mustoe 2016 paper referenced above.  This paper is a free download at the below link:

 

https://www.researchgate.net/publication/302776353_Origin_of_Petrified_Wood_Color

 

 

 

 

Most of the green wood from Hampton Butte is a cast versus replacement, so there isn’t any cell structure in the cast pieces to ID the species.  I don’t see cell structure in this piece.

 

Petrified Replacement Wood, Eocene 34 to 40 MYA, Clarno Formation, Hampton Butte, Deschutes County, central Oregon (1 lb. 1.6 oz. 7 x 5 x .5 inches):

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

I also have a number of pieces of green petrified wood from Indonesia, all cut from the same log.  See the two group pictures, two individual slab pictures (taken with my camera indoors, using flash, with the slabs dry) and a close-up picture (taken with my Dino-Lite microscope) of the wood cell structure below:

 

 

 

 

 

Polished Petrified Wood, Indonesia (1043 grams, 215x145x18-20mm)

 

 

 

 

Polished Petrified Wood, Indonesia (1000 grams, 225x140x16mm)

 

 

 

 

Wood cell structure:

 

 

 

 

Marco Sr.

[MarcoSr]

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 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 which further demonstrate these concepts.  See white oak and southern yellow pine examples below.

 

 

 

 

 

 

 

 

 

 

 

 

 

Marco Sr.

Edited October 19, 2021 by MarcoSr
added two wood type examples

[MarcoSr]

Below are pictures of a slab of Texas petrified shrinkwood [following preservation, the piece became fractured and healed with agate (brecciation)] with awesome colors and crystallization.  The type of wood cannot be identified because there isn’t any remaining identifiable wood cell structure.  Only one very small area of the piece has any evidence of cell structure.

 

Petrified shrinkwood, Miocene Fleming Formation, Live Oak County, Texas (176 grams 4.25x3.5x.375 inches):

 

 

 

 

 

 

 

 

 

 

 

 

 

Marco Sr.

[MarcoSr]

I really like these two pieces, not because of the petrified wood itself (the driftwood lacks cell structure to ID it), but because of the Teredo borings and the encasing algae.

 

Teredo Bored Petrified Driftwood, Middle Miocene, Saltos Shale Member Monterey Formation, Santa Barbara Canyon near Cuyama CA (510 grams 6.25 x4.5x.625 inches):

 

 

 

 

 

 

 

 

 

 

 

Petrified Yew (Taxus sp.) in Stromatolitic Algae, Miocene Tertiary Volcanics, Tonopah, Nevada (60grams 3.25 x 2.5x.19 inches):

 

 

 

 

 

 

 

 

 

 

 

 

 

Marco Sr.

[KOI]

Very cool collection. You even have ostracods in the specimen from Blue Forest!

For those who interested in permineralized wood, I would recommend this movie, which features a bunch of typical types of "petwood" and plenty of info. 

 

[MarcoSr]

On 10/10/2022 at 1:04 AM, KOI said:

Very cool collection. You even have ostracods in the specimen from Blue Forest!

For those who interested in permineralized wood, I would recommend this movie, which features a bunch of typical types of "petwood" and plenty of info. 

 

 

Great video.  Thank you for posting.

 

Marco Sr.

[MarcoSr]

Here are close-up pictures of a few more interesting petrified wood slabs:

 

 

The below pictures will help you to identify what you are seeing in the close-up pictures of the Tempskya sp. tree fern slab.  I really like the colors and details of this slab.

 

 

 

 

 

 

 

Tempskya sp. slab, Cretaceous, Harnett County, North Carolina (114 grams 5.25x2.75x.19 inches)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

This petrified wood piece has really nice colors including blue and hints of the wood grain and wood cell structure.

 

 

Petrified Wood, Miocene 23 to 5 MYA, Hubbard Basin Elko County Nevada (1031 grams 7.75x3.25x1 to 2.5 inches)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Marco Sr.

[MarcoSr]

I recently added to my collection this piece of very colorful petrified wood with fungal cavities.

 

Petrified Wood with Polyporites wardii fungal cavities, Triassic Chinle Formation, Kanab, Utah (297grams 4.5 x1.75x1 inches):

 

 

 

 

 

 

 

 

 

 

 

 

 

Marco Sr.

[Rock Hound]

This thread deserves a big thumbs up.  Nice specimens.

[MarcoSr]

On 8/22/2021 at 8:37 AM, MarcoSr said:

I really don’t/didn’t  find much petrified wood at the marine sites that I collect in MD and Virginia, so unfortunately I had to buy most of the petrified wood in my fossil collection like the slabs in the above posts.  I do find a good amount of small pieces of lignitized wood especially in the Eocene, Nanjemoy Formation of Virginia.  I have found small pieces of petrified wood, usually either embedded or partially covered with Pleistocene bog iron, in Virginia.  My son Marco Jr. found, by far, the nicest piece of petrified wood that I’ve seen from marine sites in MD/VA, in the Miocene, Eastover Formation of Virginia, 5 or 6 years back.  See the below pictures.

 

Petrified log from the Miocene, Eastover Formation, of Virginia (33 inches long, 28 inches around at the base, over 100 pounds).  These pictures were taken in my driveway.:

 

 

 

 

 

 

 

 

Marco Sr.

 

A short update on the Miocene, Eastover Formation of Virginia, specimen.  I tried to donate this specimen to the USGS and to the Smithsonian on behalf of my son, Marco Jr.  Although there was initial interest, both decided that they did not want the specimen.  I had given small pieces to both organizations, which unfortunately on examination, showed no internal wood structure, which caused the specimen to have very little scientific value.  Although the specimen seemed petrified from the outside, it began to degrade, crumble and split.  I didn't have the vessel to soak or the chemicals to stabilize such a large piece.  It was breaking down from the inside out.  The specimen finally broke into a number of large pieces.  Seeing the inside of the specimen made it obvious that the piece was in a very unstable state of preservation between lignitized wood and petrified wood.  Seeing that the piece would continue to degrade over time, my son asked me to discard it.  So I kept a small piece and the rest wound up in my woods.  A sad ending for what originally seemed like such a promising specimen.

 

Marco Sr.

[grandpa]

[MarcoSr]

I'm posting the below closeup pictures to show a vesselless dicot wood structure.  The latter pictures are at a higher magnification.

 

Petrified Wood, Vesselless Dicotyledon Angiosperm,, Trochodendraceae Tetracentraceae or Winteraceae, Trout Creek Form, Miocene, Zimmermann Ranch near McDermitt, Nevada/Oregon (176 grams 5.5x2.625x.375 inches):

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Marco Sr.

[Bobby Rico]

Wonderful collection. I have enjoyed catching up on this thread.   

[MarcoSr]

I just received the below Petrified Wood slab.  It has really nice colors and very good wood cell structure, so I am posting the below pictures.  The seller stated that she thought it was from the Pacific Northwest, but I think it is more likely from the Southwest.

 

Petrified Wood, Pacific Northwest???? (516 grams 5x4.75x.25 to1 inches):

 

 

 

 

 

 

Marco Sr.

 

 

 

 

 

 

 

 

Marco Sr.

[grandpa]

14 hours ago, MarcoSr said:

very good wood cell structure

Indeed!

[MarcoSr]

When I normally buy petrified wood from Indonesia, I buy brightly multicolored, highly agatized wood.  However, the highly agatized Indonesian wood usually doesn't have a lot of really nice wood cell structure.  I bought these slabs because of the wood cell structure.  I'm posting only a few pictures of many that I've taken for each slab, because they show the detail that I want to show and to keep the MBs down for this post.  The highest magnification pictures below really show the detailed wood structure of these petrified wood pieces.

 

70 Petrified Wood Slab, Indonesia (494 grams 7.25x4x.5 inches):

 

 

 

 

 

 

 

71 Petrified Wood Slab, Indonesia (606 grams 7x4.5x.625 inches):

 

 

 

 

 

 

 

 

72 Petrified Wood Slab, Indonesia (565 grams 8.25x4.75x.5 inches):

 

 

 

 

 

 

 

 

 

73 Petrified Wood Slab, Indonesia (589 grams 6.5x5.5x.625 inches):

 

 

 

 

 

 

 

 

74 Petrified Wood Slab, Indonesia (643 grams 6x4.75x.625 inches):

 

 

 

 

 

 

 

 

Marco Sr.

 

[MarcoSr]

I just received a number of Teredo wood pieces from Indonesia (See first two pictures).  The next pictures show two of these pieces and close-up pictures.  These pieces have nice wood cell structure throughout.

 

 

 

 

 

75 Petrified Teredo Wood, Sumatra Island, Indonesia (464 grams 5.75x3.75x.625 to .75 inches):

 

 

 

 

 

 

 

 

 

 

76 Petrified Teredo Wood, Sumatra Island, Indonesia (309 grams 6.5x3.5x.375 to .5 inches):

 

 

 

 

 

 

 

 

 

 

 

 

Marco Sr.

[Yoda]

@MarcoSr

 

That Toredo wood looks really interesting. 

Not seen it before. 

 

Fantastic photography and close ups as usual. 

[MarcoSr]

3 hours ago, Yoda said:

@MarcoSr

 

That Toredo wood looks really interesting. 

Not seen it before. 

 

Fantastic photography and close ups as usual. 

 

I've seen a good bit of it lately from Indonesia.  They must have uncovered a supply of it on Sumatra Island, Indonesia.

 

Marco Sr.

[Yoda]

@MarcoSr

 

What age is it ?

[MarcoSr]

29 minutes ago, Yoda said:

@MarcoSr

 

What age is it ?

 

I don't know for sure, but Indonesia's largest deposits of petrified wood come mainly from drastic volcanic activity and flooding around 20 million years ago.

 

Marco Sr.
‎

[Tidgy's Dad]

This thread is great.

Informative and with some stunning photos!

[MarcoSr]

I just received a number of quarter druzy pocket hardwood slabs from Indonesia.  Each of the slabs has a slightly different color tint from natural to grayish to reddish to yellowish.  All the slabs have very nice wood cell structure.  I took over 100 pictures but I am only posting a few here.

 

Druzy Pocket Hardwood Slab, Lampung, Indonesia (85 grams 3.75x2.875x.25 inches):

 

 

 

 

 

 

Drouzy Pocket Hardwood Slab Lampung, Indonesia (95 grams 3.25x2.375x.375 inches):

 

 

]

 

 

 

 

 

 

 

 

Druzy Pocket Hardwood Slab Lampung, Indonesia (124 grams 4.5x2.5x.375 inches):

 

 

 

 

 

 

 

Druzy Pocket Hardwood Slab Lampung, Indonesia (132 grams 4.75x2.75x.31 inches):

 

 

 

 

 

 

 

 

 

 

 

Marco Sr.

Edited March 21 by MarcoSr
Palmwood to Hardwood

[snolly50]

Lovely pieces and outstanding photos. I very much enjoyed seeing this.