Naked Science Forum

Non Life Sciences => Geology, Palaeontology & Archaeology => Topic started by: JoshNZ on 26/08/2016 01:22:00

Title: Is this a petrified apple?
Post by: JoshNZ on 26/08/2016 01:22:00
A friend of mine brought this into work today, he thinks it is a petrified apple. Can anyone confirm exactly what it is? Anything anyone could tell us about it would be interesting, what is it likely made of, how it formed etc... Does it have any value? It weighs about 300grams, hard as stone and almost looks like iron oxide on the surface.

He also brought in an interesting stone i thought was worth sharing. Appears a stone has got tangled up in another stone and through some process of erosion is now a captured ball within the larger stone. Quite cool I thought!

Thanks in advance for any help!
Josh
Title: Re: Petrified apple? + cool stone
Post by: JoshNZ on 26/08/2016 01:28:45
Photo 2
Title: Re: Petrified apple? + cool stone
Post by: JoshNZ on 26/08/2016 01:30:09
Photo 3
Title: Re: Petrified apple? + cool stone
Post by: JoshNZ on 26/08/2016 01:32:41
Photo 4

I do have high resolution photos but size here is limited and external links are not permitted. If anybody is interested I could upload elsewhere.
Title: Re: Petrified apple? + cool stone
Post by: chiralSPO on 26/08/2016 02:31:03
Regarding the "apple":
It definitely looks like iron/iron oxide on the surface. Thank you very much for sharing the mass of the object, and for showing a picture with your hand in it for scale, this is very helpful. Based on the photo, it appears to be nearly spherical with a radius of about 2 cm. If it has a mass of 300 g, that translates to a density of almost 9 g/cm3, which is VERY dense for stone. Iron, however, has a density of about 8 g/cm3. Therefore, I guess that the object is slightly larger than 2 cm radius, and is composed almost entirely of iron. It could be a naturally occurring iron nodule (somewhat unlikely) or meteorite (less likely), or a man-made artifact (most likely--perhaps it was an iron statue of an apple, or a small cannon ball, or something else...)

Regarding the stone-in-stone:
Very cool! My best guess is that the smaller round stone was somehow trapped in the surrounding stone as it formed. The outer stone might be sedimentary, in which case, the smaller stone got surrounded by silt/clay type stuff, which was eventually compacted into stone. This sedimentary rock then eroded (weathered) away to reveal the smaller older stone, which is apparently more resistant to erosion/weathering.
Title: Re: Petrified apple? + cool stone
Post by: JoshNZ on 26/08/2016 04:03:53
Before anybody goes doing any math let me get some more accurate numbers for you. I measured its volume by water displacement, 105mls which makes it 105cm3 right? I don't have a set of scales at work but will weigh it when I get home, I suspect I have been way off with my guess. I would be very surprised if it was an iron mould, looking inside the core, it is nothing like iron, more like nut/wood.

As for the stone inside stone, they look identical in composition whatever it is. The smaller ball is able to rotate freely inside the recess of the larger stone too, like a bearing in a housing. As if it has been sitting there in running water doing it for a while.
Title: Re: Petrified apple? + cool stone
Post by: RD on 26/08/2016 06:31:07
Quote from: JoshNZ on 26/08/2016 01:22:00
... he thinks it is a petrified apple ...
Vegetable-matter may have been involved : ironstone concretions (https://en.wikipedia.org/wiki/Concretion) can form around plant roots, the root rots-away leaving the hole ...

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.nhm.ac.uk%2Fnatureplus%2Fservlet%2FJiveServlet%2FdownloadImage%2F2-8106-9979%2F450-294%2FImage%2B1.jpg&hash=b7940a014c9b96e56695b20fdec6ac91)
http://www.nhm.ac.uk/natureplus/thread/3324?decorator=print&displayFullThread=true


(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.thenakedscientists.com%2Fforum%2Findex.php%3Faction%3Ddlattach%3Btopic%3D68139.0%3Battach%3D22125%3Bimage&hash=87af4a25bfcfdabb692eac9dea9646b1)
Title: Re: Petrified apple? + cool stone
Post by: RD on 26/08/2016 06:50:02
Quote from: JoshNZ on 26/08/2016 01:32:41
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.thenakedscientists.com%2Fforum%2Findex.php%3Faction%3Ddlattach%3Btopic%3D68139.0%3Battach%3D22129%3Bimage&hash=a6d047f2d882408238515b86dbbc606d)

https://www.google.com/search?site=&tbm=isch&source=hp&biw=1280&bih=687&q=gogotte+geology&oq=gogotte+geology
Title: Re: Petrified apple? + cool stone
Post by: JoshNZ on 26/08/2016 08:28:24
As I thought, my guess was way off. It weighs 131grams, and is 105cm3 - if that changes anything.

I have uploaded a video of a little look around both, for a better idea of the apple anyway. The stone is just cool! See links below

Captured Stone
youtube.com/watch?v=jlIJdshdmS4

Apple
youtube.com/watch?v=1MtxbTw9E8I

As you can see it doesn't appear to be stone or iron inside the apple...
Title: Re: Is this a petrified apple?
Post by: JoshNZ on 31/08/2016 04:06:30
Is consensus then that this is not a petrified item? If it were not man-made, could it be anything else?