Clast in conglomerate: wood, bone or not fossil?

[CornelDumitru]

Please help me ID this component of a conglomerate block found in Romania, Harghita county.

Compared to the rest of pebbles and matrix, it is outstanding in every way: size, shape, internal structure.

There is no reaction to vinegar and all considered, I would say it is a piece of chalcedony.

Did the silica replaced wood, bone or not a fossil?

Thank you!

 

 

 

 

 

 

 

 

 

Diameter is ~45 mm, lenght ~90mm.

 

[turtlesteve]

I am seeing a rock clast - likely a feldspar rich gabbro, bordering on anorthosite.  There is some foliation so it could debatably be a metagabbro.  The feldspar is predominantly labradorite which is what’s producing the flashes of blue color.

 

Edited September 6, 2021 by turtlesteve

[CornelDumitru]

11 minutes ago, turtlesteve said:

I am seeing an igneous rock clast - likely a feldspar rich gabbro, bordering on anorthosite.  The feldspar is predominantly labradorite which is what’s producing the flashes of blue color.

 

Uh... I have polished many feldspar pieces and this here is not feldspar. The blue is not in flashes, it is stable while looking from different angles. This is cryptocrystalline silica, my bet.

Thanks!

 

[Rockwood]

Fern.

[CornelDumitru]

42 minutes ago, Rockwood said:

Fern.

Thank you!

I thought about fern earlier today and searched Google with not much success.

Now that you propose fern, I did the search again.

There is a TFF topic "Tree fern?" where you replied.

There is a photo on flickr by James St. John looking similar to my specimen (on the outside), Psaronius.

I wonder. 

 

Edited September 6, 2021 by CornelDumitru
clarity

[Rockwood]

Possibly. A definite ID may be in reach with a little polish. And a more polished eye looking at it. 

[Rockwood]

I wonder. @paleoflor

[CornelDumitru]

1 hour ago, Rockwood said:

 a little polish.

 

Polish is done since Sunday.

There was a wavy axial crack, weakened by acid bath, that gave up precisely when I triumphantly took the piece up from the last lap on the machine.

So I glued it back together and it sits in a vise for the night.

In a short time I will post photos with all the glorious long veins. Which, by the way, can be seen in the centre of the 5th photo where the saw disk passed a bit close to the specimen.

 

Edited September 6, 2021 by CornelDumitru
clarity

[Rockwood]

[CornelDumitru]

Photos of polished specimen:

 

 

 

 

 

 

 

 

Dimensions are 42 x 74 mm.

 

[CornelDumitru]

13 hours ago, turtlesteve said:

I am seeing a rock clast - likely a feldspar rich gabbro, bordering on anorthosite.  There is some foliation so it could debatably be a metagabbro.  The feldspar is predominantly labradorite which is what’s producing the flashes of blue color.

 

 

My first reply to you may have been wrong. I took some close-up photos. 

 

 

 

 

 

 

mm grid on paper.

 

[FranzBernhard]

Deformed igneous, perhaps gabbroic-anorthositic, rock.

Franz Bernhard

[Rockwood]

No contest. The guys are right.