Stumped on this Rock, any ideas?

[landapugs]

My name is Daniele.  I am new to this forum but have been collecting for a few years.  I live in Central Ohio and have access to a creek on my property.  I believe it connects to the Licking River, but not sure.  It floods when it rains and so always a lot of "stuff" to find.  Lots of erosion as well so I don't only get sedimentary rocks, but other kinds as well.  and Flint.  Lots of flint.   
Anyway, I found this rock awhile ago.  I'm almost sure it was in the creekbed, but honestly I set it aside and forgot all about it until last night.  Then the books came out and identification is hard.  I think it's Limestone, or Travertine, but what are those green crystals and that orangey smooth shiny stuff on it?  Any help appreciated!
Edit:  to add - I should have posted this in the rock category, but not sure how to move it there.  Can a moderator move it for me?  Sorry!!

[painshill]

Hi Daniele and welcome to the forum.
I moved your post (which you can’t do yourself) and brought the thumbnail pictures up to full-size (which you can do yourself… click on the “insert” button next to the pictures before you click on “submit”… or do that afterwards via the editing option for your post).
I suspect that the matrix may well be travertine (which is a type of limestone). I can see a fibrous texture and some pitting – both of which are typical for travertine. The green and the orange material could be different forms of calcite (most probable), or chalcedony, or one calcite and one chalcedony.
The simplest way to check is from the hardness. Calcite has a hardness of 3, so it will just scratch a US cent coin but will not scratch a penknife blade. Chalcedony has a hardness of 6-7 and will easily scratch both of them.
Incidentally, all of Ohio’s exposed and surface geology is sedimentary. Chert and flint are both sedimentary rocks. Although the State does have metamorphic and igneous rocks, they are deep underground. The only non-sedimentary rocks you will find at or near the surface are erratic depositions from pebble to boulder size arising from glacial transport – largely from the Canadian Shield.

[landapugs]

Thank you so much for your response.  I am looking at images of Travertine with calcite and chalcedony and I think you are right on.  I will do the hardness test to make sure.
Also, thanks for the information sedimentary rocks.  That is good to know.    Thanks again! 

[denby957]

I am also stumped on this rock that I found and I believe it is tektite maybe meteorite it seems to be metal but does not look like a piece of metal it is very very magnetic and very heavy to be so small any input is appreciated

[painshill]

Hi Denby, and welcome to the forum.
Just a gentle nudge that it’s not good form to climb onto someone else’s post with an unrelated find… better to start your own new thread and give it a helpful title.
The prospect of identifying what you have from small pictures and the properties you have described and no indication of where you found it is rather low I’m afraid. However, it isn’t a tektite. Tektites are essentially composed of amorphous glass (melted silica) and are non-magnetic.
The odds of it being a meteorite are also rather low. An iron meteorite which is anything other than a very recent fall will always have a rusted surface because the iron is present as native metal (together with nickel). The vast majority of highly magnetic rocks that people find which don’t look metallic and are not rusted usually turn out to be one of two things. Fragments of man-made industrial slag, or pieces of hematite containing magnetite as a secondary mineral. Hematite is a very dense mineral but shows almost no attraction to a magnet unless magnetite is also present.
Give it a streak on the back (unglazed) side of an old bathroom tile. An iron meteorite will leave no streak. Hematite streaks red and magnetite streaks black, so many iron-bearing rocks which are mixtures will streak a dirty brown. Man-made slag also doesn’t usually leave a streak, so the test is not conclusive.

[denby957]

Sorry about piggybacking the post I am still figuring out how to use the site and your information is appreciated  it was found in south tx and I was told it was most likely a recent meteorite  (i.e. shooting star) as he said . It does have rust on it and I found this  piece.  Definitely not man made Slag very slick and weighs about 3 oz but it is very strange to me is only reason I am asking.  Thanks for your time and sorry about the piggybacking this post again.  Just signed up here about an hour ago

[painshill]

denby957 wrote:

Sorry about piggybacking the post I am still figuring out how to use the site and your information is appreciated  it was found in south tx and I was told it was most likely a recent meteorite  (i.e. shooting star) as he said . It does have rust on it and I found this  piece.  Definitely not man made Slag very slick and weighs about 3 oz but it is very strange to me is only reason I am asking.  Thanks for your time and sorry about the piggybacking this post again.  Just signed up here about an hour ago

  No problem.
There is absolutely no possibility for that small item to weigh in at 3 ounces (85 grammes) or anywhere near that. It would need to be made out of a rare earth metal (iridium or something) to even approach that weight and then it wouldn't rust or be magnetic. Here's a nickel iron meteorite of typical density from the Canyon Diablo Crater in Arizona. I estimate it to be around the same size as your item, and it weighs about 11 grammes!

Did you try the streak test?

[denby957]

Well I am serious about the weight of the whatever it is.  It weighs a lot and I thought it was crude iron ore because of its weight and all of my tile is attached to my bathroom and all glazed.  It is strange as I said.  If you know of any other ways of testing it or some one that I can have look at it I will gladly send it to them I found this piece while hunting for arrowheads. It is definitely over 1 oz but it feels like a weight that I use when fishing on the coast ,usually a 3 oz lead surf weight  that is twice the size of this . I will see if I can find a small  scale  and post a picture of the exact weight  later today

[denby957]

Found this in Bulverde tx

[painshill]

A close-up of with the kind of sharpness as for the picture I posted might help.
There's a big difference between 3 ounces and one ounce!
Most outlets that sell tiling materials will usually have a broken tile or two that they're happy to give you. Failing that, a neighbour who has done any DIY work might have a leftover. Failing that, the inside of the lid on your toilet tank will be unglazed ceramic

[denby957]

It does leave a black Mark on the inside of the lid . I wouldn't have thought of that and I' live in apartment complex so no neighbor's do diy but I'm not saying it is or isn't from just this test but you seem to have alot more knowledge about it ??

[painshill]

denby957 wrote:


It does leave a black Mark on the inside of the lid . I wouldn't have thought of that and I' live in apartment complex so no neighbor's do diy but I'm not saying it is or isn't from just this test but you seem to have alot more knowledge about it ??

  I've collected meteorites for 30 years or so and have a large collection! There's at least one other long-term collector here on the site. Anyone who has given you advice and is using the term "shooting star" probably doesn't know much about meteorites I would suggest. 
The black streak is good for magnetite (or a magnetite-rich rock) and not what you would get from a meteorite. I think that when you get a more accurate weight, you'll find it's not as heavy as you initially believed.

[denby957]

Well I don't think you are wrong about it and I haven't got a clue what it is and I appreciate the information that you have provided . I also have a few other things that I have found and if you can help me with they were found in south tx also but one is a fossil for sure but I'm not sure about the other one. They both stick to my finger like a bone does when I wet my finger and touch them. That's how I test bone

[painshill]

I think your “adhesion” test for bone is an unreliable diagnostic. There is no evidence of anything which resembles bone structure in either of those items.
The first piece is igneous or metamorphic rock which has intrusive veins of what is likely quartz. There’s nothing fossil-related there.
The second piece could conceivably be a fossil, but it’s certainly not bone. It might be an imprint of something shelly. There appears to be a remnant of what might be something nacreous shining at 6 o’clock towards the bottom in the first picture of it. I’m more inclined to think it’s a bit of opalisation, which is not uncommon in cherts and that what you have is a pseudofossil. I think it’s banded chert.
Some cherts and flints show a series of roughly parallel lines, either as three dimensional ridges or a surface pattern. The lines vary in how far apart they are and how straight or curved and they may change direction or end abruptly. They’re frequently mistaken for fossils.
The mode of formation for banded flint and chert is not known for certain. Some geologists believe the bands represent “stop-start” rhythmically deposited silica from solutions of different concentrations over a period of time; some believe them to be caused by movement of water during lithification; and some believe them to be compression or stress features created before lithification was complete. I’m inclined to believe the latter when the bands are complex and have a strong relief.
Here’s a few examples (the first three pictures are from the UK Natural History Museum blog):




[picture from Jurassic Coast Museums Partnership website]
They sometimes have more exotic 3D shapes, like these (from the posters Keith Little and Roy Shepherd respectively on the UK Fossils Network “discussfossils” forum:


  None of the above specimens have a fossil origin… they’re purely geological oddities.