Petrified Mushroom?

[ynot]

5 hours ago, Rockwood said:

Glass would look much the same, but would pass this test.

Anyone know a test to differentiate it from rock ?

Since glass is made from silica sand and has the same specific gravity and hardness as quartz, the only way I know of (to be sure) is a gas chromatograph.

[fossilized6s]

Looks plastic to me as well. 

[Sagebrush Steve]

7 hours ago, Rockwood said:

Glass would look much the same, but would pass this test.

Anyone know a test to differentiate it from rock ?

If you are a little bit mechanically inclined you could try to measure its specific gravity.  Here is a thread that describes a couple of ways.  But if the specimen is not a homogeneous material the results will probably not be very accurate.

 

 

[Sagebrush Steve]

2 hours ago, ynot said:

Since glass is made from silica sand and has the same specific gravity and hardness as quartz, the only way I know of (to be sure) is a gas chromatograph.

Although the specific gravity of glass will vary depending on the additives.  Leaded glass can have a specific gravity of over 3, while soda glass is about 2.4 - 2.5.  Quartz is 2.65. A specific gravity test won’t be definitive but can rule out some possibilities.

[coffin05]

i weighed it earlier and it has a weight of 76 grams...i am going to put it in a graduated cylinder next to find its displacement and hopefully find a specific gravity of something close to it.

[Kane]

15 minutes ago, coffin05 said:

i weighed it earlier and it has a weight of 76 grams...i am going to put it in a graduated cylinder next to find its displacement and hopefully find a specific gravity of something close to it.

Have you tried applying heat first to determine if it is plastic?

[coffin05]

yes i was able to cut a small sliver from the nicer side of the yellow cap..the opposite side is harder and crumbled shards came off which were brittle.the sliver i was able to get off i placed it on a blade and put flame to it and it caught fire instantly and burned in about 2 seconds leaving just a thin curved piece similar to whats left when paper is burned..i then picked up the leftover and it was just like a piece of soot from a chimney..when it burned it was extremely quick and a thick sooty smoke puffed from it, but it did not melt or drip..it was almost like a quick flash and no odour that even remotely smelled of plastic...it gave off a nasty odour similar to an old piece of musty rotten wood being burned...nothing even close to the smell of any plastic...im completely stumped now since all along i thought the whole thing was hardened not just part of it...when i dug it up it was encased in sandstone and pebbles which were cemented to it and i spent a good few hours carefully removingt the sandstone..it was located only a few inches above the bedrock with a few coal seams and a lot of different layers of shale ,stone, slate etc which is about 100 feet above the bedrock...it came from inside the bank where i was digging into collecting small gemstones from the old river bed which comes out of the bank but is also flush with the bank so digging into the bank is the only way to follow the old river bed...if you are interested i would send a piece to you for your own hands on examination....i find it difficult to explain with just pics....anyone that has picked it up agree its not plastic mostly because of its texture and it feels a lot heavier than plastic for its size when holding it...it feels about the weight of an average rock of similar size..

[Rockwood]

Plastic is a very general term. If it burns the odds greatly favor it being some sort of man made material. (humanite) 

The odor sounds similar to that given off by the casting resin used to make fake amber pieces. 

[coffin05]

when it burned up so quick and the smell of rotten musty wood burning was the odour and the flake left behind was like a piece of soot from a chimney..as soon as i touched it the black flake also resembled soot on my fingers....also i couldnt understand how a man made item could be so far into a bank with about 100 feet of ground above it...i was standing on mostly bedrock and used a pick and spade shovel to dig into the side of the bank..i found it about 3 or 4 feet in

[Rockwood]

I remember watching my mother cast jewelry as a child. Resin has been around at least 50 years. A river moves a lot of material in that amount of time. 

[Bobby Rico]

It is a puzzle . The object may have been at the top of the bank and moved to the bottom in a mudslide. Just a thought.

[coffin05]

this area is full of plant and tree fossils in the bank also and there are what look like seeds about the size of chestnuts and walnuts but shaped differently...these are embedded in the bedrock and i had chipped around those also then brought them to my shop to clean them up....by the way my shop has nothing to do with fossils , its an automotive repair shop..i also found a fossilized tree standing upright inside the bank where i was digging in a different spot in same area and also a depression in the bedrock about 4 feet in diameter which looks like an old nest of sorts, its full of fossilized sticks embedded in the bedrock in a well arranged fashion inside the circular depression...all around it is where these seeds are embedded,,luckily i was able to retrieve a few of them...im gonna dig up some pics of what looks like a nest , the seeds and the piece of the tree i was able to break off

[Rockwood]

[Sagebrush Steve]

20 hours ago, coffin05 said:

i weighed it earlier and it has a weight of 76 grams...i am going to put it in a graduated cylinder next to find its displacement and hopefully find a specific gravity of something close to it.

Good idea but be aware it is such a complex shape you will have difficulty getting water to wet all the surfaces without trapping lots of air bubbles and giving you an incorrect reading of displacement.  Adding a couple of drops of liquid detergent to the water will lower its surface tension and make the measurement more accurate.

 

This is a very interesting specimen.  I wonder if it is someone’s failed attempt to cast an artificial mushroom for some sort of artistic purpose.  The photo of the underside shows what appears to be a stem, so I can understand why you might think it is a petrified mushroom.

[coffin05]

it took a bit of time but i found my graduated cylinders....also used a drop of dish soap and moved the what i call a mushroom around and shook it under water till all the trapped air came out...both object and water were at 20 degrees C and after calculation the SG came out to be 3.3043....i looked up plastics and resins and couldnt find any with a SG higher than 2.1

[ynot]

There are only a couple of geologic structures that will burn. (sulfur, coal or copal)

Your item is obviously not one of them.

Amber and copal are very lightweight. Coal is black. Sulfur is yellow and has a distinct smell.

This leaves man made material as the only option for Your object. Maybe it is a type of rosin or fiberglass.

 

What do You think @Sagebrush Steve.

[Sagebrush Steve]

7 minutes ago, ynot said:

There are only a couple of geologic structures that will burn. (sulfur, coal or copal)

Your item is obviously not one of them.

Amber and copal are very lightweight. Coal is black. Sulfur is yellow and has a distinct smell.

This leaves man made material as the only option for Your object. Maybe it is a type of rosin or fiberglass.

 

What do You think @Sagebrush Steve.

I am also leaning toward manmade.  The OP seems to have been able to cut off a small piece of it to do his burn test, which would mean it isn’t very hard. It burned, so it’s probably not geologic.  It looks a bit old, so I’m thinking it might be one of the early thermosetting plastics from the 1920’s like Bakelite.  Perhaps someone threw it away after it partially melted in a fire?  Hard to say for sure without having it in my hands to do some testing.

[ynot]

3 minutes ago, Sagebrush Steve said:

early thermosetting plastics from the 1920’s like Bakelite.

I think bakelite is a good possibility on this one.

[Sagebrush Steve]

12 hours ago, coffin05 said:

it took a bit of time but i found my graduated cylinders....also used a drop of dish soap and moved the what i call a mushroom around and shook it under water till all the trapped air came out...both object and water were at 20 degrees C and after calculation the SG came out to be 3.3043....i looked up plastics and resins and couldnt find any with a SG higher than 2.1

That makes it even more difficult to identify.  It is in the range of some types of glass but I am unfamiliar with any forms of glass that will burn the way you described.  The link I posted above about how to measure specific gravity includes a table at the back listing the SG for various stones.  Jade, peridot, and some types of garnets are in that range, but again they wouldn’t burn.  My best guess would be some sort of early 20th century plastic that had some sort of additives to give it color that increased its density.  But I am way out of my area of expertise so this is just a guess.

[doushantuo]

as posted by Troodon:

[KimTexan]

“Pebbles, sand stone and cemented” these words used to describe a rock form sound a bit like what concrete looks like. Could it have been a concrete type substrate that is used in sidewalks and such?

I’m curious about the seeds, nest and tree you found. A fossilized upright tree and a nest sound like very unusual finds in a riverbed embankment of all places. Over the eons or millennia I would have expected water to have disturbed them. 

Were they found in the same general location as this item or did I misunderstand their location in respect to this item?

[Rockwood]

4 hours ago, KimTexan said:

I’m curious about the seeds, nest and tree you found. A fossilized upright tree and a nest sound like very unusual finds in a riverbed embankment of all places. Over the eons or millennia I would have expected water to have disturbed them. 

Were they found in the same general location as this item or did I misunderstand their location in respect to this item?

Sounds very similar to the Joggins cliffs. A well known site in NS.