FMF - Friends of Minerals Forum, discussion and message board

[B Glassburn]

Hello
I recently found a piece of fulgurite with small light blue 'specks'. It has very tiny black and clear crystal s, visible with a loop, as well. This piece is not a tube, but rather a clump. It was found in a creek, where the light blue specks shown up brilliantly, but when dry not so much. This is definately a natural fulgurite. Could these light blue specks be stishovite?

[Peter Lemkin]

Hello and welcome. What makes you so convinced it is a fulgurite? Have you compared it to the photos here https://www.mindat.org/gm/7747 ? Most, but not all, fulgurites have a central tube, and you are not showing us any in the one photo you posted. There is also a discussion of fake, erzotz, and suspect fulgurites on the same forum. Some posts are helpful, others are as bad as non-fulgurite 'fulgurites'. https://www.mindat.org/mesg-187540.html I don't mean to pop your balloon, but just wanted to know how you are so certain it is a fulgurite. Many people think are, are not. Perhaps yours is, just asking.
What was the ground matrix where it was found? As they are 'popular' now with the 'crystal healing set' and expensive, so there are people making things they say are fulgurites, but were not naturally created by lightning, but by artificial means.
Perhaps you have done your research on this specimen and my questions are out of line. By the way, some fulgurites have xx formed with them and also complex organic molecules - even fullerines - sometimes form [non-crystaline to the eye, if crystaline at all]. There are now some pretty good techniques to tell with high certainty if something is or is not a fulgurite, but it takes equiptment usually found at universities et al. However, one can get a pretty good idea by eye, if one knows what one is looking for and how most of them look. If one types the word julgurite into a search engine and pdf after, there are several papers one can get - although some have to be paid for to blue-meany publishing companies. I found enough for free to learn a lot about them and some papers listed associated minerals that also form in tiny xx depending on the temperatures, pressures and compounds/elements present in the matrix struck by the lightning.

[B Glassburn]

Yes, it is a fulgurite. I recently went to a stone knappers' event, and a vendor there had two for sale, and I was able to get a positive i.d. on it. Granted, it was found in a creek, so water may have tumbled it around a bit. I thought it was a novelty at first, a blue speckled leverite, then when I was researching shocked quartz it got me to wondering.... It is my understanding that not all fulgurite have tubes, then again this could be just a piece of a larger one that has become water-worn. The original matrix is ??? again thanks to the moving water. However, the area it was in is rich in silica.
I also understand that fulgurite from lightning forms at ultra-high temperatures, as does fulgurite formed from meteor impacts or nuclear events; while some fulgurite can form at lower temperatures by downed powerlines or other man made devices. Though this piece lacks the central tube, it does display characteristics of melted and fused quartz.

[Peter Lemkin]

You say you got a positve ID on it. By whom? The stone knapper who sold it to you? Pardon my being skeptical until there is some validation by an expert of some kind opining on what it is or is not. We get many who start their first post with 'I found this diamond' or 'I found this aerolite', etc., when it is nothing of the kind. Fulgurites are somewhat rare, although there are likely many that are 'seen' but missed by the untrained eye. Even the 'trained eye' rarely finds one. Most have been found in desert sands, apparently - but elsewhere too, as lightning strikes most places and they could form most places but the ocean.

[B Glassburn]

Thanks for your input. No, no one sold me this piece. I have a background in aggregate testing, pit certification, and civil engineering. I have a good eye, have been rockhounding for 40+ years back in Western Washington, where there's a lot of volcanic activity. Now retired in upstate New York, where there is much less volcanic formations and much more metamorphic things going on so this is a bit of a learning experience.
This piece is non-magnetic, and non-flourescent. It does display a glassy luster under the rough surface. There are some pretty good universities and museums near me where I can contact their geology departments and maybe take it in.
An interesting note, due north of where this piece was found is the east end of Lake Ontario. About 11 years ago scientists found an impact crater underwater in the east end of the Lake. I am not saying this piece is a result of that event, but it was while researching Shoemaker, shocked quartz, and impact craters that I led me to believe this piece was more than a leverite. I am reading up on fulgurite formation now, found a good paper one Researchgate to start.

[Josele]

In this blurry photo it looks like a rhyolite pebble more than fulgurite. Well focused close-up images can help a lot but maybe a petrographic study is needed to be sure.

[Matt_Zukowski]

I doubt we will be able to help you further. I recommend you go to a Univ or museum and talk to someone in person with the rock in hand.

[B Glassburn]

Will do. I have a good size collection that I mostly display for kids at the local library. I like to include things that 'wow' the kids and get them interested. Things like this I love to put in the display, but only if I have a positive i.d., so I can answer questions for the kids. And if and when I do get anymore info, I will gladly share it.
Sorry about the blurry photo, we have 3 macro cameras in the family, unfortunately mine is not one.

[Peter Lemkin]

Yes, children [and adults] find fulgurites of interest! However, as this one lacks the hollow core and has been perhaps water-worn, I think it needs confirmation. I believe most types of the new mineralogical testing techniqus can distinguish the type of quartz and other fused minerals one finds in a fulgurite from other minerals with a high degree of probability. Ramen spectrography might be your best bet, as it is quick and not expensive for the reasearcher to use - especially mobile Ramen units. It is always a little bit of problem to interest and get some time commitment from someone with such equiptment, but it often can be done. New York State has some very good geology departments and museums, as does Canada in the Montreal region. Good luck. Stishovite is rare and usually found in aerolites - Sio2 formed under extreme pressures and also takes very specialized testing to identify it. A quick look on the internet did not produce any associations with fulgurites, but I did not spend much time on that and I never trust the 'ranking' of items web browsers produce as necessarily being most relevant. High pressures and temperatures are indeed produced in the formation of a fulgurite. Again, good luck.