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It Was Labeled "hematite After Wood"


Mediospirifer

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Mediospirifer

Last month, my husband found this piece labeled "Hematite After Wood Minnesota" at a rock shop.

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The piece is about 7 cm long by 2 cm wide between the bulges.

I have some doubts about the "After Wood" part of this label. The bulges look more botryoidal than barklike, and I don't see any distinctive woodlike structure on the broken ends. I could easily be wrong, though. :)

Here are some better-illuminated pictures:

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Do I have a really cool mineral replacement fossil here, or a really wild-looking pseudofossil? If the former, I'll include it in my mineral club open house display this Sunday. If the latter, I might include it in a mineral club display on pseudofossils next year! :D

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I don't see a fossil there, but it has some nice crystal structure, It does look like hematite in the picture.

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Nice specimen of haematite. It was described as "after" which could be taken as meaning "looks like" but doesn't imply any more than a passing resemblance.

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Definitely a pseudofossil. Looks like botryoidal Hematite or possibly Goethite. The latter is found here in Pennsylvania among heavily oxidized iron deposits called "Bog Ore" where is forms large hollow geodes called "bombs" (since they sometimes look like rusted WWII bombs I assume). Here is a page with specimens that look similar to yours from Minniesota and some Pennsylvania stuff too.

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Mediospirifer

Thanks, guys!

That's pretty much what I was thinking. My husband is disappointed, though.

Neither of us have heard of "X after Y" terminology being applied to something where "Y" was never present in the first place. I thought it was possible that the seller had misidentified it. There were a few other things with odd labels for what they were, including a nice piece of tree fern fossil labeled as "Kingston Lode Ore"! I figured someone on TFF could settle the question for this one.

It's an excellent specimen of hematite or goethite, and I'm not disappointed with the price of it.

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It is my understanding that "X after Y" does denote a replacement, at least in the mineral world. So it sounds like someone misidentified something (in part).. happens all the time!

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It is my understanding that "X after Y" does denote a replacement, at least in the mineral world. So it sounds like someone misidentified something (in part).. happens all the time!

I think what we have is a mix up in terminology between disciplines, in antiques, where it is fairly commonly used, "X after Y" is used to mean looks like, not replaced by. I sometimes think we should simplify the English language.

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I think what we have is a mix up in terminology between disciplines, in antiques, where it is fairly commonly used, "X after Y" is used to mean looks like, not replaced by. I sometimes think we should simplify the English language.

I'm sure there are some things that could be simplified, but I think within each discipline things are generally simple (because they're already complex enough that nobody would want to add unneeded complexity to it), even if it's not the same usage as in other disciplines - so trying to make a 'grand unified' system for all of them might make the whole thing way too complicated for anybody to understand because it has to deal with everything under the sun rather than with just those few things dealt with by a given discipline.

Hmmm.. As usual my way of describing things is probably unnecessarily complicated!

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There was dicsussion on another thread recently about fossil pseudomorphs. The "X after Y" terminology in the mineral world generally refers specifically to a situation where the second mineral has taken on a crystal shape which is not one of its natural crystal forms. Generally that happens when the second mineral occupies a void left behind by the first mineral and is "forced" to adopt that shape. The term has however been extended to cover "[mineral] after [organic fossil]". There are a few examples here on the mindat site of minerals "after shell" and "after wood".

http://www.mindat.org/forum.php?read,82,207457,page=1

I would agree that the example being shown here is not that kind of pseudomorph.

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Classic case of technical usage and common usage of the language not matching. Not the first time I've seen this and it won't be the last.

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Mediospirifer

Thanks, guys! I'm glad there's a consensus.

This piece will be on display at our mineral club open house on Sunday, but not as part of my fossil types display. I'll offer it to one of my fellow club members for her table of crystal shapes.

Sunday, Feb. 2. 1-5 PM at the Museum of the Earth in Ithaca, NY, if any nearby TFF members want to check it out. That's the Museum's Free Day, so there won't be any admission charge. The Museum is well worth visiting!

The discussion of language differences between disciplines reminds me of how confusing I found the term "double-blind" in my different science classes. That meant something different in sociology than it does in biology or psychology!

Edited by Mediospirifer
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