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Post by johnw on Dec 13, 2018 23:03:31 GMT -5
So here's the story. About 65 million years ago, give or take a few million, whoever was walking upright at the time got involved in an altercation with an adversary who had a knife. Being without any weapon he reached down and grabbed a rock from the muddy ground and tried to defend himself. Clearly he had an issue and parried the thrusts of the knife many times and apparently he eventually won the day by clocking his adversary in the chops and got to live another day. He then threw the rock away and walked into history. Fast forward to current times and yours truly just got it for his collection from eBay. A fictional narrative to be sure, but in fact what you see are either stab marks or the thrust of some animal pecking into the soft, at that time, material, looking for food............... Here is the piece of history: Images by myself and Taasher  To me, these look like stab marks from a sharp, well honed knife. But there is probably some other reason for this appearance that my second comment may just cover, these marks are the result of some animal pecking the soft surface. Anyway, those are are my theories, the first one being pure fantasy, the second being just a guess. Does anyone care to comment on how these marks may have originated? Here it is another side of the piece.  Clearly, this dude really enjoys his food and likes to show you what he is eating.   Another image  The stab marks are directly above on the flat surface. Final two images   Cheers, johnw |
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Post by fernwood on Dec 14, 2018 4:21:21 GMT -5
That is a beautiful piece. I often find rocks with the same type of crevices. Dunno how they happen for sure. One theory is decomposition of softer material over the years.
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Post by johnw on Dec 14, 2018 4:40:16 GMT -5
That is a beautiful piece. I often find rocks with the same type of crevices. Dunno how they happen for sure. One theory is decomposition of softer material over the years. Thanks, it really caught my eye too, now its part of the collection. I can see what you describe as being decomposition over time but what gets me is the knife like impressions are so numerous. It would be interesting to put this under a scope.Yeah, sure, but not he one that ate all my images.  Cheers, johnw |
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Post by greig on Dec 14, 2018 9:46:13 GMT -5
To my eye, the vug and lacerations look natural. Still, stick to your story because it is a good one! I have taken rocks to a gunfight...usually trying to break a large rock with a 45/70. Sometimes, the rock wins (doesn't break). ;-)
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Post by johnw on Dec 14, 2018 12:27:50 GMT -5
To my eye, the vug and lacerations look natural. Still, stick to your story because it is a good one! I have taken rocks to a gunfight...usually trying to break a large rock with a 45/70. Sometimes, the rock wins (doesn't break). ;-) Hi greig, the lacerations seem to me to be too uniform to be of natural origin. There are multiple knife shaped "holes" in the surface that would preclude, I think, a natural evolvement. Alternatively, those could have also been made by a sharp beak from some prehistoric animal and this is more than likely since the piece is only 3"x2.5"x3" and weighs 1.2 pounds. I did not show an image size verification in support of my first narrative which was my first impression when I saw the piece on eBay. "Wow, this has been in a knife fight" and so that was the Subject for the post. Dramatic sure, but it does kinda get your attention.. The vug I agree is a natural phenomenon, except for the "food particles". Have a great day......Cheers, johnw |
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Deleted
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Post by Deleted on Dec 14, 2018 12:55:37 GMT -5
Far more likely that what you have is a nice example of an epimorph. A deposition of different material flows over and/or coats an existing plate of crystals (I think calcite or some evaporite are candidates on yours). Later, those crystals dissolve and are not replaced, leaving a hollow reverse impression of the dissolved crystals. You might do a latex cast of some of the sharper hollows to determine what were the original crystals.
Epimorphs are in contrast to pseudomorphs (where the hollows in an epimorph are filled with a third mineral, then the second coating material dissolves or weathers away).
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Post by johnw on Dec 14, 2018 16:39:18 GMT -5
Far more likely that what you have is a nice example of an epimorph. A deposition of different material flows over and/or coats an existing plate of crystals (I think calcite or some evaporite are candidates on yours). Later, those crystals dissolve and are not replaced, leaving a hollow reverse impression of the dissolved crystals. You might do a latex cast of some of the sharper hollows to determine what were the original crystals. Epimorphs are in contrast to pseudomorphs (where the hollows in an epimorph are filled with a third mineral, then the second coating material dissolves or weathers away). Hi rocks2dust, ...got it and Googled and got confirmation and you are spot on. I am seeing the point (not to make a pun) and if I look at other sections of the piece there are a lot of minerals that could have been subject to what you describe but most all of the crevices are on a flat plain which confirms the point the original material flowed. Dang, that's good, but I'm gonna keep the subject title and the narrative going cuz' it makes for a good story. AND, at first glance it does lend itself to be seen as having been in a knife fight. Thanks for shedding light on the subject so we can all understand. Cheers, johnw |
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Mark K
Cave Dweller 
Member since April 2012
Posts: 2,818 
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Post by Mark K on Dec 14, 2018 17:52:40 GMT -5
I've never seen anyone bring a rock to a knife fight, but I HAVE seen a guy bring a knife to a gun fight.
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Post by johnw on Dec 14, 2018 20:52:29 GMT -5
I've never seen anyone bring a rock to a knife fight, but I HAVE seen a guy bring a knife to a gun fight. Hi Mark K, I'll take a rock in a sock anytime over a knife. A rock in a sock wielded correctly will crush a skull, break a wrist, smash an arm, demolish an elbow, shatter a collarbone, take out a knee, shove a nose into the brain, take out an eye, demolish a larynx and make mush out of testicles. Plus you can take it on a plane as a pet rock in a sock. Urahhh, special ops basics, when no weapons are available. So when you are on a plane and a little old lady reaches in her purse and pulls out a stone egg and then a sock, puts the egg in the sock, give her all the respect she deserves............God Bless America. |
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Post by stephan on Dec 14, 2018 21:09:21 GMT -5
Far more likely that what you have is a nice example of an epimorph. A deposition of different material flows over and/or coats an existing plate of crystals (I think calcite or some evaporite are candidates on yours). Later, those crystals dissolve and are not replaced, leaving a hollow reverse impression of the dissolved crystals. You might do a latex cast of some of the sharper hollows to determine what were the original crystals. Epimorphs are in contrast to pseudomorphs (where the hollows in an epimorph are filled with a third mineral, then the second coating material dissolves or weathers away). I was thinking evaporite as well. |
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RWA3006
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Member since March 2009
Posts: 4,640
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Post by RWA3006 on Dec 14, 2018 21:40:25 GMT -5
Far more likely that what you have is a nice example of an epimorph. A deposition of different material flows over and/or coats an existing plate of crystals (I think calcite or some evaporite are candidates on yours). Later, those crystals dissolve and are not replaced, leaving a hollow reverse impression of the dissolved crystals. You might do a latex cast of some of the sharper hollows to determine what were the original crystals. Epimorphs are in contrast to pseudomorphs (where the hollows in an epimorph are filled with a third mineral, then the second coating material dissolves or weathers away). This. I have a couple specimens that still have some of the original crystal material embedded in the casts as if frozen in time. Looks very similar to yours. |
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Post by johnw on Dec 14, 2018 21:55:15 GMT -5
Far more likely that what you have is a nice example of an epimorph. A deposition of different material flows over and/or coats an existing plate of crystals (I think calcite or some evaporite are candidates on yours). Later, those crystals dissolve and are not replaced, leaving a hollow reverse impression of the dissolved crystals. You might do a latex cast of some of the sharper hollows to determine what were the original crystals. Epimorphs are in contrast to pseudomorphs (where the hollows in an epimorph are filled with a third mineral, then the second coating material dissolves or weathers away). This. I have a couple specimens that still have some of the original crystal material embedded in the casts as if frozen in time. Looks very similar to yours. Awesome, is it possible you can upload some images? Here is the best I can do without a scope attachment. Cheers, johnw  |
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RWA3006
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Member since March 2009
Posts: 4,640
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Post by RWA3006 on Dec 14, 2018 22:06:37 GMT -5
Love to but afraid it's buried somewhere under the snow out in the piles. Seems I saw more somewhere years ago on a hounding trip but I left them in situ.
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Post by johnw on Dec 14, 2018 22:11:39 GMT -5
Love to but afraid it's buried somewhere under the snow out in the piles. Seems I saw more somewhere years ago on a hounding trip but I left them in situ. No issue and thank's anyway. On the image above, I do see some crevices with material inside. Is this what you remember? Cheers, johnw |
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RWA3006
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Member since March 2009
Posts: 4,640
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Post by RWA3006 on Dec 14, 2018 22:59:05 GMT -5
Yes, and even more. The one I picked up has a gradual transition that shows the empty casts phasing up to being filled with material up to couple inches thick. I've also found chalcedony with a similar patterns in southern Utah. I always assumed it was formed up against some kind of crystals and then they weathered away leaving casts.
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Fossilman
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Member since January 2009
Posts: 20,723
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Post by Fossilman on Dec 15, 2018 10:52:40 GMT -5
Yes, and even more. The one I picked up has a gradual transition that shows the empty casts phasing up to being filled with material up to couple inches thick. I've also found chalcedony with a similar patterns in southern Utah. I always assumed it was formed up against some kind of crystals and then they weathered away leaving casts. Same thing with Carnelian agate in Washington and Oregon.....I have some in my shop like that.. |
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Post by woodman on Dec 15, 2018 11:51:39 GMT -5
sorta of like this piece of Carnelian.  |
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Post by johnw on Dec 15, 2018 13:15:47 GMT -5
sorta of like this piece of Carnelian. woodman, awesome beyond words. This guy has been to and survived an axe fight. Do you have dimensions for this baby? Cheers, johnw |
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Post by woodman on Dec 15, 2018 14:27:11 GMT -5
sorta of like this piece of Carnelian. woodman, awesome beyond words. This guy has been to and survived an ax fight. Do you have dimensions for this baby? Cheers, johnw 6" by 5 1/2" x 4" . In looking at it, I do need to clean it. I have had it for a number of years and never had the heart to cut it up. |
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Post by Lapidaryrough / Jack Cole on Dec 15, 2018 16:45:07 GMT -5
Pillow basalt below water table, with a high content of calcium carbonate in solution From all living sea life an mollusc calm bone waste an so on. flowing into the gas pockets in the pillow basalt gas pockets below sea level. give or take a few million Bp. years. As the plate is uplifted out of salt water to high Silica water . then agate starts to cap over the Calcium carbonate crystals in the gas pockets.
As you seen in Brazilian agate pillow basalt agate. same much larger forms of calcite crystals.
In Oregon carnelian agate. Lebanon,Oregon Home town to ME.
Calcite footprint roots away leaving a cast in the carnelian agate.
Great material on Oldsodaville Rd. & Rockhill Rd.
Jack
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Cheers, johnw
