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MeteoritesTektites with Brown

25th Aug 2009 01:50 UTCGordon c De'young

We are finding these in Oregon,So far all the test are saying they are indeed tektites.I am however afraid to send off the brown colored ones.I think they need to cut them open?Dr Weller of Cochise college, in Arizona and others are performing the test.Unfortunatly we are going to have to wait to find more the winter weather help's in washing the silt off of them and the ground freeze pops them up out of the ground.So far we have two locations 20 miles apart as a bird fly's.These have been cleaned currently we have 3 five gallon buckets full of them.I suppose besides woodcarving ill be cleaning tektites(but will leave some dirty for the testing) we also have alot of the silty soil they are found in.The samples pictured from 2.7cm to 4.2cm the Brown colored one measures3.2cm

25th Aug 2009 04:06 UTCByron Thomas

Im sorry but I have to say no to the Tektites. What you have there are obsidian bombs the giveaway is the brown streaked one. It is a dead giveaway for mahogany obsidian.


Sorry



Byron

25th Aug 2009 11:23 UTCPavel Kartashov Manager

Tektitic glasses should be very differ from obsidianes by their water contents. Tektites are almost dry, while obsidian contains 1-2 % H2O or more (perlite glass).

So you need in precise water content determinations in your glasses.


Besides that, finding of such phases as moissannite or native metals (Si, Fe, Ni etc.) in heavy concentrates from your glass may to confirm its tektitic nature.


By the way, I never saw "obsidian bombs". From other hand, these objects are similar to some indochinite specimens.


Kind regards,

Pavel

25th Aug 2009 13:36 UTCAlfredo Petrov Manager

I agree with Byron that these are obsidian pebbles, abraded and etched by surface weathering.

25th Aug 2009 14:04 UTCPavel Kartashov Manager

Yes, they may be pebbles (with little bit strange structure of surface for water abrasion). But really not a bombs.


In any case water content determination isn't hard accessible and expensive test. Oregon isn't Upper Volta. ;)

25th Aug 2009 15:10 UTCSteven Kuitems Expert

Gordon, I am curious as to the fractured sample with the two light grey spherical inclusions. These should be tested. There is a possibility that they may turn out to be the high temperature silicon dioxide cristobalite and this may verify Byrons idea. So I would encourage you to have these areas analyzed. Steve.

25th Aug 2009 15:31 UTCPavel Kartashov Manager

07433690016027830751380.jpg
Steven is quite right! Such spherulites (blue arrowed) are very often observed in obsidians ( and synthetic glasses) and consist of different silica polimorphs (cristobalite, tridymite) and anortoclase mixture (both silica and feldspar are fibrous). By the way similar, but much more smaller, spherulites with tridymite I observed in "Libian glass" tektites also. Tektites had cool too fast for large spherulites formation (as we can see on the photo), but may to contain them (especially in large/massive tektite pieces).


If this material really contain tektite particles, only two from the picture are similar to tektites (yellow arrowed).


From my point of view, it is enough to break such "tektite" and obvious obsidian specimens and compare outer view of broken surfaces of both. If they are the same, all material is obsidian.


25th Aug 2009 16:07 UTCByron Thomas

Ok not bombs but still obsidian.


Byron

25th Aug 2009 16:08 UTCMike Jensen

Hi Gordon


It is almost certainly obsidian. Here is a photo that shows obsidian with cristobalite from California;

http://www.mindat.org/photo-5103.html

Notice how the crystals are radiating spheroids in both photos.


If you need more here is a great test that most of us non scientist types can preform;


from O'Keefe, John A 1976 Tektites and Their Origins


A tektite is a natural glass, usually black, but sometimes green, brown or gray, which occurs in lumps, usually a few centimeters in length, having no chemical relation to the local bed rock. Tektites are broadly similar to some terrestrial volcanic glasses (obsidians); they can be distinguished by heating to the melting point with a blowpipe or a blowtorch. Obsidians turn to a foamy glass, while tektites produce a few bubbles at most, because of their much lower content of water and other volatiles. Under the microscope, obsidians are seen to have abundant microlites (microscopic crystals); tektites have essentially none.


Here is a excellent article that shows pictures of the results of the blowtorch test;

http://www.meteorite-times.com/Back_Links/2003/January/Jims_Fragments.htm


I actually get that same question several times a year. Unfortunately in almost 15 years I have never had any pass the test.


Good luck with your test.


Mike Jensen

25th Aug 2009 17:41 UTCPavel Kartashov Manager

The similar in simplicity test is:

take 1 g of tested specimen crushed in powder and heat it up to 1000o C in furnace. After cooling weigh it. If you have obsidian, it will give 900 mg or less. If you have tektite - its weight still stay around 1 g.


Really it is hard busines to look for tektites along Western coast, too much obsidian spread in this region.

25th Aug 2009 19:03 UTCAdam Kelly

I still think Tektites, but the brown one is odd.

Can't wait to see what the results of the tests are!

25th Aug 2009 19:26 UTCAlfredo Petrov Manager

No blowtorch or fancy apparatus necessary - a kitchen gas flame is quite sufficient for this test. And those of you who have an electric range in the kitchen should toss it and get gas flames - they are just simply way too useful for mineralogical tests!

25th Aug 2009 20:32 UTCKen Doxsee

Ah yes, the kitchen gas flame. I still remember well my exploits when I was about 12 years old, generating a whole lot of metallic mercury by heating mercuric oxide over the stove. A lot of the mercury condensed in the test tube. I can only imagine how much didn't, and how much I inhaled. Kids, don't try this at home!! ::o --Ken

26th Aug 2009 01:05 UTCGordon c De'young

Back in May of this year a professor from Southern Oregon University,Dr. "Smede" sent off a few of my tektite samples the folowing is a (exert)from a letter in responce from Dr Fiske.of the," Department of Mineral Sciences National Museum of Natural History Smithsonian Institutite"in the {qoute} "The box arrived today,and i showed the stone to Linda welzenbach,She's not a tektite specialist,but on first glance she said it sure looks like a tektite.So i would bet that it was a tektite.{end qoute} Still waiting on paper work as well as Dr Weller, and his test results.

26th Aug 2009 02:14 UTCAlfredo Petrov Manager

So she admits she isn't a specialist; she just looked; did no tests... and then proclaimed it "sure looks like a tektite". Why am I not impressed?

Please, Gordon, forget about museum opinions; just do the necessary tests yourself - It isn't difficult.

26th Aug 2009 12:45 UTCJolyon Ralph Founder

Alfredo,


Sadly it IS very difficult to do a test, however simple, that could turn your valuable tektites into worthless obsidian.


Such is human nature.

26th Aug 2009 16:10 UTCGordon c De'young

Hello Alfredo, would you please explain. I tried this with a small sample i stood over the stovef or over a half an hour holding the specimen in big needle nose pliers.Nothing exciting happened, i did manage to drop it and it cracked in even smaller pieces.I then placed the even smaller piece over the fire.No foaming and i dont really want to call what it did bubbling either it seemed more like plopping and now it has tiny lil pimples.A few of them not many.Ill wait for the smithsonian and Dr Weller, Of Cochise college to do the real testing.After all theres no real hurry anyways.I dontplan on going back to the source until the spring anyways.For me its woodcarving time(i am a full timewoodcarver) thanks everyonefor all your wonderful input.If and when these are indeed verified as being tektites i will be giving many away to collectors who ask.PS..Alfredo. i was mearly pointing out how the head of the department at the Smithsonian Institute thought they might be tektites Wouldnt you agree she must have an educated guess? i mean that is a respectiful post she has isn't it? Also Dr Friske, also says at first glance they appear to be,yes i know apperance can mean many things but you have to remeber how many of these have these people actually seen and the respected positions they hold at the Smithsonian,Iforgotto mention Dr Smede,of Southern Oregon University, did perform test and they came back positive he simply sent some off to the Smithsonian, because of the number of samples found and the location.

26th Aug 2009 18:00 UTCAlfredo Petrov Manager

Gordon, probably your sample didn't get hot enough, because the sample was too big, and the pliers conducted too much heat away. Smash a big piece and select a sharp little splinter, and hold that in the flame with a thin iron wire. (Hold the iron wire with a wooden clothes pin, so you dont burn your fingers.) I think you'll get better results, and it will take only seconds; no need to stand there a long time. Good luck!

27th Aug 2009 00:48 UTCGordon c De'young

Thanks,Alfredo i did it this way and the results were bubbles,no rapid foaming stuff.

27th Aug 2009 02:16 UTCAlfredo Petrov Manager

Bubbles, and even pimply swellings, indicate a small water content in the glass. (Foaming would have meant a relatively big water content, as in perlite.)

Warning: Testing stuff becomes addictive! Have fun.

Alfredo

27th Aug 2009 16:54 UTCGordon c De'young

We give up it will be best to wait on the experts.we tried this test again and almost absolutly happened except a minot very faintchange in colorof the sample.My friend tells me the bubbles from the attempt was the copper coated wire i used.

27th Aug 2009 18:02 UTCMark Gottlieb

Gordon:


Please keep us posted as your inquiry into these objects progresses; this has been an interesting thread to follow. Personally, I am betting on "not tektites", although I have seen a bunch of similar looking objects offered for sale as tektites.


You may want to check up on some of the Mindat posters - these folks really know what they are talking about and are the "experts". Just so you know, there are some big time museum professionals lurking in the background on Mindat. Perhaps some of them will chime in on the debate.


Mark

27th Aug 2009 19:51 UTCLachrisha Smith

This is a great topic!! Dr. Kring explained to me how to find tecktites!!! simply put,.. like this,..tecktites are simular to obsidian,and if you find a tecktite,..go up hill from where you found the first tecktite, and it can lead you to more,although I seem to be a magnet for them,..I find that they are around New Mexico in great numbers. also, in Arizona. but, this should be the case! nevertheless,it can lead you to a meteorite as well, with the right eye...they can be found.tecktites are more dull, not as shiny as obsidian.and testing can be a great way to further your knowlege!! most tecktites are hundreds and thousands of yrs. old.

28th Aug 2009 18:30 UTCGordon c De'young

Dear Gordon: Boy, am I embarassed! I am so sorry that we at the Smithsonian have let you down so badly. The basic problem is that our department (in the Museum of Natural History) has no person familiar with tectiites. A couple of our meteorite specialists looked at the sample and said, "It sure looks like a tectite," but none of these people could definitely say, Yes, it is one." They mentioned the name of a specalist (at some other institution) who could examine it, and one of our staff even said she'd send it to him. I, mistakenly, thought she had done that and that everything was in order. But it obviously was not. I'm living in Seattle for the summer, so it's hard for me to deal with this issue right now. But I'll be returning to the Smithsonian on September 7th, and I could try to get things back on track soon after that. In particular, I could send your sample to that specialist, and you could soon have a definite answer. Is that OK with you? Regards and regrets, Dick Fiske P.S. Please tell Harry Smedes that I'm not a bad guy--- just a sometimes disorganized guy! i just received this message a little while ago strang he mis spells(lol) Well we still have Drw Weller, at Cochise college in Arizona.And hes a very busy guy he leads up the geology dept.and has explained he hasto create two new classes fore this year as well as his other duties.I am will to send samples(dirty ones) to anyone all they need to do is ask.In return i ask that if any testing is done i would like to have copies of the results.

2nd Sep 2009 04:48 UTCGordon c De'young

Well i recieved this e-mail today from Dr Weller.{quote}.. Gordie,




I finally got a chance to take a closer look at the “tektites”.




I am still somewhat caught on a definitive answer.




On the plus side:

They are the correct color, overall shape, the are definitely glass, correct size range, and some have surface features similar to tektites.


On the negative side:

I broke a real tektite from the Australasian fall for comparison. It was difficult to break the Australasian tektite; it took several tries. Your tektite broke much easier. However, both appeared to be a shiny black glass. Breaking easier makes me suspect that your tektite might have a higher water content. Real tektites have an extremely low water content, while obsidians have a fairly high water content.


Next, your tektite on a thin edge of broken glass has a light gray color with just the very slightest tint of green. The reason that green is so important is that at the high temperatures at which tektites are created, oxygen is driven out and the iron present is all converted to ferrous iron, giving the tektite a strong green color. The moldavites are all an intense green. The Australasian tektites are a dark brown with a green tint; their color comes from the ferrous green plus a reddish color from submicroscopic spherules of iron that were injected into the glass when the meteorite struck the ground. Your tektite only has a bare hint of green; it resembles some obsidians. There is a hint of some layering or color variation in you tektite. I lack a gem cutter’s diamond saw to make a thin slice of the tektite to examine it thoroughly.


The avocado surface texture is different than the surface of any tektite that I have ever observed. On the other hand, some of your tektites do have surfaces very similar to those found on real tektites.




I am still caught between the two possible origins: tektites versus volcanic glass. The main feature that will determine the answer is the water content of the glass. I checked on the Internet and I have the names and address of some geologists who might be interested and who can perform the necessary tests. If you want to, you can mention my name and title as referring you to them.




S.S. Hughes, J.W. Delano, and R.A. Schmidt

Department of Chemistry and Geology

Oregon State University

Corvallis, OR 97331


I hope this helps a bit. I would love for these stones to be real tektites, because it would represent a new fall.

But I am cautious because of the large amounts of obsidian that have erupted in the Oregon area.




Sincerely,

Roger Weller

16th Oct 2010 01:24 UTCAnonymous User

Pardon the lateness of this addition to the topic. I assume you have received your answer by now- these samples will almost certainly be obsidian. I have samples from Healdsburg, CA, Safford, AZ, southern NV and from Peru. I have seen photos of remarkable specimens from New Mexico, Columbia and Chihuahua State in Mexico.

Most of the above varieties have been analyzed and they are obsidian. Healdsburg glass is the most troublesome one to place- like a tektite it is quite dry, has a very high fusion temp and some reduced-phase iron; but abundant microliths would be hard to explain in a tektite and Healdsburg is full of them.

I have found over 750 bediasites and one georgite and collected some obsidian(?) specimens near Healdsburg. I collect tektite analogs and I am always open to adding more specimens from different locations.

Should you recover specimens that are teardrop or dumbell shaped and they are glass then you can get excited- the likelihood of being a tektite would be very great!


Happy hunting,

Briman

11th Jan 2011 20:24 UTCBri Dragonne

If these were all found in the same general area, then they will certainly be Obsidian nodules due to two facts:


The brown one is certainly Obsidian of the variety (Or market name...) Mahogany Obsidian.


The gray spheres inside are certainly Cristobalite.


That being said, it is highly improbable that a few tectites managed to randomly fall in the same area as the other, certainly Obsidian pieces.


It would be like finding a random plastic apple at the bottom of an apple tree, mixed with the natural apples already on the ground, I should imagine ;)


-Bri

7th Feb 2011 16:38 UTCKarie

hello, found your comments on tektites, by now maybe you have found out if the tektites are indeed real. We also live in So Oregon and have found what we think are tektites. Did you ever send them to get tested in Corvalis ? Karie

31st May 2013 22:08 UTCAlicia

This is a nice feed to find. I was just in the area this last weekend and went looking for the " Healdsburgite ". I happen to be at a wedding with a Chemist from the Nebraska, and a showed him a sample that I found on the intersection of Lytton and Dry Creek Road at a road cut. We both seem to have a very similar reaction to the sample, that it looked more volcanic than the elastic dimple round shapes that I researched online from Professor Rolfe Erickson online collection. However, this sample is being taken back to the University of Nebraska to the Geology department to have it looked at.


My only one question is could the fact that 2.8 billion years ago and the increasingly tectonic activity possibly alter the chemistry of the tektite through pressure and or cooking. In the same area I found a great number of wonderful samples of quartzite in the strong calcite and potassium coloring. However I am a student and may be over my head on this, but I'd still like to see the outcome and others thoughts, provided this string is still attached to known emails.

6th Dec 2015 06:08 UTCRobert Verish

09932420016027830759625.jpg
Since this thread started (back in 2008) access to XRF hand-held analyzers has become easier, fortunately.

Through the use of an XRF unit, I have found a method to quickly distinguish between obsidian and tektites.

My interest in this subject began when I recently found a rare variety of greenish-yellow/brown obsidian. (see photo)

I am aware of all the published obsidian source locations close to my find locality, but none of them seem to

properly match my obsidian. I realize that paleo-trade-routes involving obsidian can cover great distances.

So, obviously I'm still looking for the source of this obsidian.

In the meanwhile, I've started to write a paper about a new technique to test between obsidian and tektites.

When it is finally published, I will add a link to it, here.

12th Feb 2016 12:56 UTCReiner Mielke Expert

Thanks Robert,


Looking forward to the results as I am sure a lot of other people are as well.

19th Sep 2016 06:15 UTCSandra Briggs

I have found ones like yours here in Oregon but mine are smoother and very magnetic. I would like to know where you sent them to be tested as i would like to send mine there.

19th Sep 2016 08:13 UTCRobert Verish

Thanks for the tip about there being a locality in Oregon. I would sure like to test a specimen from that locality.

Tektite experts have told me that if my natural glass specimens are "very magnetic", I can forget about it being a tektite.

On the other hand, I have tested impact-glass from various craters and some of them are attracted to a magnet.

Coincidently, I just posted an article on this subject where I presented the preliminary test results of 60 specimens

that I tested with a handheld "XRF". Here are the links:


http://www.meteorite-times.com/bobs-findings/part-2-tektite-or-impactite-or-obsidian-pseudo-tektite/


and my blog with updates:

http://meteorite-recovery.tripod.com/2016/sep16.htm

23rd Sep 2016 09:49 UTCRobert Verish

Hello Reiner Mielke ,


My name is Robert Verish, and I made a post/reply to this thread "Tektites with Brown" (color).

Here is the link to my previous post:

http://www.mindat.org/forum.php?read,98,149850,393711#msg-393711



You are also one of the several people that have replied to this thread, and you also requested to be given "updates" if there was any new information. If you are no longer subscribed to this thread, you may not be getting "updated".

I have not received any replies to my latest post (Sept 2016), so I have decided to reply directly to you, and your earlier request.


In my last post, I was trying to explain that, while I was conducting tests on specimens of tektites and obsidian, I have stumbled across a "simple" test method that (so far) has consistently been able to "quickly" distinguish between volcanic-glass (obsidian, i.e. marenkites) and impact-glass (especially, tektites) . I was using a handheld Niton XRF for this testing. Although getting access and using an XRF may not be considered "simple", getting test results was certainly "quick". With only a minute of X-ray irradiation, test results are immediately displayed on a screen.


I recently published an article on this process where I presented the preliminary test results of 60 specimens of obsidian and tektites that I tested with this handheld "XRF". To see these results, here are the links:

http://www.meteorite-times.com/bobs-findings/part-2-tektite-or-impactite-or-obsidian-pseudo-tektite/


and my blog with updates:

http://meteorite-recovery.tripod.com/2016/sep16.htm


This testing is still on-going, so contact me via personal message, if you have a potential tektite specimen, or have an unusual greenish/brown obsidian that you would like to have tested.

23rd Oct 2016 03:03 UTCRusty Shackleford

Soooooo, is Healdsburgite a tektite...?

19th Jun 2017 22:12 UTCRobert Verish

Hello Rusty,

I just now came across your question. The blunt answer is, "No!"


Every "Healdsburgite" that has been donated to me, all of them have failed both my XRF testing and the "flame-test". These results were reported in my "Bob's Findings" article that preceded the "Part 2" article that I mentioned above in my September 23, 2016 post. I won't rehash the details, but here is more information, at this link:

https://www.meteorite-times.com/bobs-findings/tektite-or-pseudo-tektite/


The above article reiterated the need for a cheap, simpler (and non-destructive) test to replace the old-school "flame-test" which was fraught with too many false-positive results (actually, insufficiently heated specimens).

I found that the hand-held Niton XRF devices to fit those requirements, except for "cheap" (unless you can beg, borrow, or steal free test-time on a friends XRF).

In any case, among the many dozens of tested specimens of obsidian and tektites, I have yet to find any overlap in the values I obtained with my XRF for Ti (titanium). All of my tektite specimens gave values higher than any of my obsidian samples. Testing is still on-going.
 
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