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JeanB

Stromatolite?

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Wrangellian

I haven't viewed your pdfs but I'm thinking, if all else fails, it might be sufficient (at least better than nothing) to find out exactly where in Madagascar this stuff is from, find an accurate, detailed map of the country to determine the age, and then perhaps get thin slices of the material to examine - maybe someone on the Forum is adept at rock identification and can tell us whether it is stromatolite or rhyolite or whatever.

But like the rest of you, I wish we could find a scientific paper to refer to - it would sure make life easier!

Your Norcross source may be completely honest in believing what they have told you, but the info is only as good as their source, whoever that is, and it is not very precise. Rock dealers seem to be satisfied with "Precambrian" for the age, while we fossilers understand that the Precambrian was almost 9/10 of Earth's history so we want something more precise!

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JeanB

I haven't viewed your pdfs but I'm thinking, if all else fails, it might be sufficient (at least better than nothing) to find out exactly where in Madagascar this stuff is from, find an accurate, detailed map of the country to determine the age, and then perhaps get thin slices of the material to examine - maybe someone on the Forum is adept at rock identification and can tell us whether it is stromatolite or rhyolite or whatever.

But like the rest of you, I wish we could find a scientific paper to refer to - it would sure make life easier!

Your Norcross source may be completely honest in believing what they have told you, but the info is only as good as their source, whoever that is, and it is not very precise. Rock dealers seem to be satisfied with "Precambrian" for the age, while we fossilers understand that the Precambrian was almost 9/10 of Earth's history so we want something more precise!

I completely agree with you. I am still trying to get the precise site of Norcross.

But here is a detailed geological MAP of south Madagascar (scientific publication in Precambrian Research)

https://dl.dropboxusercontent.com/u/78493639/Madasgascar%20MAP3.pdf

Jean

Edited by JeanB

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xonenine

my thought today is that I could make a little effort to approach it from "East African Rift" stromatolites. I have found many of the same results, papers using various mineral breakdowns, at least there are search results for the East African Rift Stromatolites...course the more recent papers will take a little shuffling, as they are on pay sites. :)

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Wrangellian

I completely agree with you. I am still trying to get the precise site of Norcross.

But here is a detailed geological MAP of south Madagascar (scientific publication in Precambrian Research)

https://dl.dropboxusercontent.com/u/78493639/Madasgascar%20MAP3.pdf

Jean

This paper (p. 124) refers to a couple other papers regarding stromatolites.. If they can be found without having to pay, they might be worth a look.

Edited by Wrangellian

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JeanB

This paper (p. 124) refers to a couple other papers regarding stromatolites.. If they can be found without having to pay, they might be worth a look.

I have the papers. I will read them but they are very technical...

Jean

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Wrangellian

All we need it a reference to 'Kambaba jasper' or 'oncolite', Maybe if we know the name of the Norcross site...?

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JeanB

Here's the email transcript of Pr. Riding concerning Kambaba Jasper:

________________________________________________________________

Jean,

Many thanks for your interesting enquiry. I had never heard of Kambaba Jasper before, and I found it a bit hard to dig through all the gemstone descriptions to try to find out what it might be. I'm still not sure but maybe it is the same as ocean jasper, also described as orbicular jasper, which according to the information below occurs in silica-rich volcanic ash.

On this USGS site:
http://vulcan.wr.usgs.gov/LivingWith/VolcanicPast/Places/volcanic_past_nebraska.html
I found this:
Nebraska's Orbicular Jasper:8
Orbicular jasper forms when a silica rich rhyolitic ash flow cools quickly. Quartz and feldspar crystallize in spherulites, radial aggregates of needle like crystals, that provide the interesting structure seen in this kind of jasper. Better known examples of orbicular jasper are often seen offered as Poppy Jasper or Morgan Hill Jasper from California or Ocean Jasper from Madagascar. The Nebraska stone has a similar structure to these latter varieties.

Wikipedia also has an entry on 'Orbicular jasper'.

And here:
http://www.mindat.org/min-27171.html

Many mineral/rock deposits can have banded/layered structure and it can be difficult to compare their origins, but if Kambaba Jasper crystallizes from hot volcanic fluids then it is not microbial and not a stromatolite.

About biofilms, it seems very reasonable to imagine that quorum sensing is pretty well as old as bacteria, which I would place at least as old as 3500 million years. But apart from comparing biofilms of that age with present-day ones, I cannot think of a way of testing this interpretation.

Thanks again for your interesting enquiry.
All good wishes for your work,
Robert


Robert Riding PhD DSc
Research Professor

Dept. of Earth and Planetary Sciences
University of Tennessee
1412 Circle Drive
Knoxville, TN 37996-1410
USA

____________________________________________________________________

I will add to this the information that (some) Kambaba Jasper comes from Mahajanga Province (Majunga), Madagascar, which is NorthWest and not SouthEast. So I am more and more suspicious that this Jasper has real biogenic origin, although Robert does not rule out the possibility.

Comments?

Jean

Edited by JeanB

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JeanB

BTW if you are interested in stromatolites here's the link to Robert Riding personal page with many pdf of his articles:

http://robertriding.com

Jean

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xonenine

thanks for sharing these Jean :)

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Tethys

Ocean jasper from Madagascar is orbicular rhyolite mined from deep in the sea and is not the same thing as Kabamba jasper. Kambaba is a silicified sedimentary rock, mined on land and similar crocodile jasper is mined in India . Ages given for the India material vary wildly, with the most common age given as 1.8 to 1.6 byo.

I tried looking for what the word kabamba might mean in Malagasy.

It appears that bamba is a corrupted translation of the word for crocodile, and the ka prefix possibly denotes a place.

(I don't trust the online translator to be accurate)

Maybe a search with french terms for crocodile, stone, oncoid, and whatever they called Madagascar during colonialism will turn up something more definite on its source and age.

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JeanB

Ocean jasper from Madagascar is orbicular rhyolite mined from deep in the sea and is not the same thing as Kabamba jasper. Kambaba is a silicified sedimentary rock, mined on land and similar crocodile jasper is mined in India . Ages given for the India material vary wildly, with the most common age given as 1.8 to 1.6 byo.

Interesting, where did you find this info?

I searched the Malagasy dictionary and looked for french links. Ka or Kam is indeed a prefix to form adjectives or modify certain words. Baba means «dad» or beautiful.

If the correct word is Kambamba: Bamba means fortification, fallen wall or covering. Madagascar minerals also use the work Aka before Kambamba. Aka has different meanings including «low tide». Mamba means crocodile (same in french).

So far it does not lead very far...

Jean

Edited by JeanB

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Wrangellian

I went on another long fruitless search last night myself for reliable info on this stuff. Apparently we aren't the only ones who have been looking and can find nothing. It's odd that every rock/lapidary seller has this seemingly confident info about it being precambrian stromatolite but we can't find their source. I'm sure they all copy each other's info, but someone had to have gotten the info from somewhere originally?

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JeanB

I'm sure they all copy each other's info, but someone had to have gotten the info from somewhere originally?

Probably, but the original claim may be lost in obscure document. I have learned that the Norcross mining site is relatively recent... How recent?: I do not know. Some sources provide more detailed description of this Kambamba stuff. Most agree on the sedimentary and stromatolitic origin. Others say that it comes from the south African rift. We have claims that this jasper may be found NorthWest or Southeast. Kambamba is a region of Africa but no region or Province of Madagascar has this name (at least in the documents I read).

I tried to find the info on India crocodile Jasper, reading the pdf of Tethys but I did not find it. Tethys, can you point me to the page?

I will meet with some mineralogists next friday. I will see what the have to say.

However, my thoughts are that if this Jasper is really stromatolite (oncolite or Collenia) it is surprising that it has not been studied by experts.

Jean

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painshill

.... my thoughts are that if this Jasper is really stromatolite (oncolite or Collenia) it is surprising that it has not been studied by experts.

Jean

I’ve been sitting on my hands trying to stay out of this debate. There's a lot of hokum and claptrap kicking around concerning this material which has created considerable confusion. “Kabamba Jasper” is an invented name for what was hailed in the fringes of the lapidary world (those I generally refer to as the “Crystal Folk”) as a new material. It isn’t. It’s a relatively newly-discovered exposure of an already-known material.

It has been studied by experts, and it isn’t stromatolitic (or even sedimentary) – at least not in the samples that have been analysed. The EPI (Institut für Edelstein Prufüng) or Institute for Gemstone Testing in Germany published a detailed report in one of its bulletins. Unfortunately the bulletins are only available to members (and only published in German). Nevertheless, paraphrasing a bit from their findings….

Thin-section and X-Ray diffraction analyses have shown that the Kabamba material it is not a type of jasper at all. It’s volcanic. The green groundmass is composed mainly of quartz, pyroxene (aegirine) with orbicles of alkali feldspar embedded with streaky aggregates comprising tiny needles of amphibole (riebeckite to pargasite). The formation is not fully understood, but it’s most likely a volcanic rock that has been “overprinted” by a weak metamorphism.

In mineral composition it’s very similar to a rock originating in Mexico that’s generally referred to in the lapidary world as “Eldarite”, although the colouration is the reverse of the Madagascan material in that Eldarite has a dark groundmass and pale orbical patterns (whereas Kabamba has a pale groundmass and dark orbicles). Eldarite is also known in America as “Nebula Stone” since, when polished, the patterns resemble nebulae in outer space.

The two rocks are nevertheless sufficiently similar from a mineralogical point of view that the EPI recommends the names “Eldarite” and “Kabamba” (with its several spelling variations) should be regarded as synonyms. They also advise that the term “Kabamba Jasper” should be replaced by the term “Kabamba Stone”.

Edited by painshill

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JeanB

I’ve been sitting on my hands trying to stay out of this debate.

My question is why?

These infos are what we were looking for and (I guess) finally put an end to this mystery. I joined this forum to learn from the experts... and I have learned a lot indeed!

Now I will be able to concentrate on real stromatolite.

You guys are all wonderful!

thanks a lot painshill

Jean

Edited by JeanB

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Spookwoman

Was looking at the word nebula stone the other night and all the "crystal" sites making claims that its powers are beyond belief and that Kambada stone is being sold as nebula stone, blahdy blah but nothing on the actual makeup etc of the stone. Might be one to pin or put into an area for safe keeping so someone else doesn't get lost in the hocus pocus internet stuff

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JeanB

Might be one to pin or put into an area for safe keeping so someone else doesn't get lost in the hocus pocus internet stuff

I agree, I was profoundly irritated by all these magical claims blurring the whole picture.

Jean

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painshill

My question is why?

These infos are what we were looking for and (I guess) finally put an end to this mystery. I joined this forum to learn from the experts... and I have learned a lot indeed!

Now I will be able to concentrate on real stromatolite.

You guys are all wonderful!

thanks a lot painshill

Jean

You're welcome Jean. I should have stepped in earlier.

I guess I held back because I have a fundamental mistrust of those “crystal folk”, the misinformation they put about and the motives for doing so. I’ve had a number of bad experiences trying to counter that kind of information with proper geological science. There are loads of these kinds of “invented” rock and crystal names which are sheer geological fantasy but aggressively defended by those that deal in them… and even by those who don’t (based on the misinformation they have read). The misinformation is almost invariably unattributed. The arguments usually spiral into assertions for “unique” locations supplemented by the “…ah but this different because it comes from…” assertions for particular materials which are no more than minor variants of something relatively common from nearby and well-known locations. It has in the past been time consuming and frustrating to try and correct the picture.

What I find even more distasteful is when there is commercial interest in selling something common under an invented name at an inflated price and it’s coupled with some metaphysical mumbo-jumbo about inner spirituality and crystal energy. Worse still when the rock in question has been trademarked, as is the case for one of the other Madagascan orbicular (non-stromatolitic) materials mentioned earlier in the thread. Here’s my chunk of that material…bought for a couple of dollars. The vendor was unable to refer to it by its accepted name because it’s trademarked and the trademarked version sells for tens of dollars… from a company that essentially operates a price monopoly.

post-6208-0-59810600-1396898685_thumb.jpg

There… I got that off my chest! :D

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Wrangellian

Thanks painshill, It's about time you weighed in! You must have enjoyed watching us flailing around looking for the info. I'll admit I'm terrible at research (and good at running off at the mouth), but I don't know whether that's because there's a trick to it or if guys like you actually have special access to literature that the average Joe like me hasn't managed to get in on.. (I know a lot of it is by pay)

So after all it is Kabamba as I thought, not Kambaba or any other spelling?

Anyway I'm glad I held off shelling out for a piece of this stuff!

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painshill

Thanks painshill, It's about time you weighed in! You must have enjoyed watching us flailing around looking for the info. I'll admit I'm terrible at research (and good at running off at the mouth), but I don't know whether that's because there's a trick to it or if guys like you actually have special access to literature that the average Joe like me hasn't managed to get in on.. (I know a lot of it is by pay)

So after all it is Kabamba as I thought, not Kambaba or any other spelling?

Anyway I'm glad I held off shelling out for a piece of this stuff!

I wouldn't be so mean as to take enjoyment from any flailing! :D

Truth is I looked at the first few posts, groaned inwardly and then shied away. I came back to the thread when I saw it had gone "hot". I spend a fair amount of time at geological fairs where I have many good contacts who are lapidary or gemological experts and I recalled discussing this material with one of them who is German. Those kinds of fairs also attract their share of "crystal folk" (both as vendors and purchasers). What I do take enjoyment from is perusing their offerings and innocently querying the heritage for many of the spurious items they sell. Tibetan Snow Cloud Stone and that sort of stuff.

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Tethys

Thanks for weighing in painshill. I think we are all very frustrated with the morass of information provided by lapidary dealers, and the lack of reliable geologic information for Madagascar.

Jasper is a category like chert. It includes a lot of rocks with very different origins., As far as I can tell, the only common element between all of the things called jasper is that they are silicified and can be cut and polished.

Red orbicular rhyolite and red silicified mudstone (sometimes stromatolitic) are common rocks in my part of the world. They range in age from Archean to Cambrian, and the true story of how they came to be here is IMO much more interesting than the misinformation provided by gem dealers.

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Wrangellian

I wouldn't be so mean as to take enjoyment from any flailing! :D

Truth is I looked at the first few posts, groaned inwardly and then shied away. I came back to the thread when I saw it had gone "hot". I spend a fair amount of time at geological fairs where I have many good contacts who are lapidary or gemological experts and I recalled discussing this material with one of them who is German. Those kinds of fairs also attract their share of "crystal folk" (both as vendors and purchasers). What I do take enjoyment from is perusing their offerings and innocently querying the heritage for many of the spurious items they sell. Tibetan Snow Cloud Stone and that sort of stuff.

I know the type you mean... I only ask the provenance of things that look interesting to me, that I might like to buy, but I find that dealers invariably know nothing (or only the most general info) about things - eg. "It's from China". I won't buy if they can't provide me with at least a specific location. Then there's the price - I saw a small piece of Tiger Iron at last month's show that I thought I'd buy for trading material (already have a larger piece myself) but the lady wanted $15 and she wouldn't go any lower than $8!

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JeanB

I am sure this whole discussion will help some of us to warn those who could be tempted by this Karamba rock! All these infos will not be entirely lost:

1) I have learned the meaning of Mamba, Kam, baba, mumbo jumbo etc. :P

2) I have geological maps of Madagascar, south India and Africa. :)

3) I now know some who got miraculously cured by standing during two hours next to a Shazam sphere :D

4) I have better knowledge of stromatolites B)

I will now look for a real stromatolite to get somewhere to use it for my microbiology teaching. Thanks again all for contributing to this discussion! It was terrific! :fistbump:

Jean

Edited by JeanB

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painshill

.... I now know some who got miraculously cured by standing during two hours next to a Shazam sphere :D

What was he/she cured of Jean?.... This perhaps?

post-6208-0-62441600-1396990808_thumb.jpg

Edited by painshill

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