Lightning Rocks - Fulgurites

[1dave]

When lightning hits the ground it usually melts and vaporizes rocks. If it hits on a sandy beach the bolt is usually broken up and scattered, making lots of little tubes in the soil.



BUT when there is something tall in the vicinity the full power of the bolt may be drawn to a single point:




Lightning Discharge in Limestone

rockpowell and I stumbled upon a power pole several years ago that is often struck.



My first collection was found scattered all over the dirt road.

[kradz89]

That's really cool! Something new to keep an eye out for!

[jamesp]

Nice collection Dave. Don't play w/lightning !!

[bsky4463]

Petrified lightening...awesome . Cheers

[rockpickerforever]

Way cool, Dave! Nice collection. Never seen one in the wild, but saw a fulgurite at a show once. A long one. Not really what I originally thought it would look like, but made sense once I saw it. Sand + 100,000 amps and temps six times as hot as the sun = fused sand, or fulgurite. Did ya find any that were still hot Dave?

[1dave]

Not hot. The road has traffic at least several times a week, so we figured it had last been hit within a few days or someone else would have noticed it . . . but then most people are oblivious about rocks, so . . .

We went back a year later and found new material, it was flying off from around the ground rod and was filled again with more melted rocks with vaporized tunnels. We got about as much stuff the second time around. We probably aught to look again.

[quartz]

Nice collection, thanks. We keep looking and hoping to find just one someday. There is a display of fulgurites that tours the western Oregon rock shows we frequent. One of them has an attached note that says it was picked while still smoking.

[snowmom]

that's really cool. I found a couple small pieces like that once and thought they were fossilized worm holes or a cast of something... but never suspected holes made by lightning! That's awesome! (I wish I had kept them)

[fantastic5]

I was backpacking Cumberland Island National Sea Shore and one of the many afternoon thunderstorms snuck up on us while we were on the beach. We had blue sky and were heading to the surf when the 4 of us heard and FELT a buzzing. We all stopped and looked at each other and within a split second lightening struck in the dunes directly behind us. I hope I never experience a strike so close again. Whole body tingled for minutes afterwards (could have just been adrenaline). Anyway my friends all though I had lost my mind when I tried to go and find the strike site. I had heard that it would fuse the sand into glass. They were all panicked and wanted to go back under the trees. I spent a few minutes looking for the site, but the storm had moved over us and I was getting hammered by rain, so I gave up the search.

Thanks for posting the pictures and reminding me of a fun day (every day on that island is both fantastic and miserable at the same time, I guess that is why I have been over a dozen times).

[Fossilman]

Crazy cool!

[jamesp]

Maybe a thick copper wire connected to a tall bamboo pole stuck in the ground out in an open field would manufacture some for you Dave.

Power poles have a ground wire on them, is that what made the ones you found ?

[jamesp]

The lightning density has some relationship w/sand. The little point of yellow crossing south Georgia line into Florida has good clay content.
Said to have washed down from north Georgia. Covering the ancient coral reefs w/clay to assist silicification.
It is my coral turf.

[1dave]

Jul 13, 2014 19:35:00 GMT -5 jamesp said:

Maybe a thick copper wire connected to a tall bamboo pole stuck in the ground out in an open field would manufacture some for you Dave.

Power poles have a ground wire on them, is that what made the ones you found ?

Zack-l-fit !
As storm systems swirl around they are huge static electric generators sucking electrons up into the clouds.

The clouds act as capacitors.







Anything moves and the electricity ionizes the area and the electrons balance things out.

The ground currents move beneath the clouds.
Here, the + reaching up the pole, and the - reaching down from the clouds joined up and ionized a path to the ground rod. I suspect in this case, power from the lines joined in the ionized fray and helped blast up rocks from around the ground rod.
Material turning into gas expands hugely in volume and blasted much of it onto the road.

I dug around the ground rod and pulled out bowling ball sized pieces.

[jamesp]

I never have looked for them. Glad I know what to look for. Sounds like you found a real honey hole.
artificially made ones :

[Deleted]

They can be found around the tops of mountains and buttes out west if there is ashy or sandy soil present instead of only boulders. Those high points do get a lot of strikes over time.

[deserthound]

in the movie Sweet Home Alabama, he drives metal stakes in the ground for lighting to hit, and it was producing really cool looking glass made by lighting. it was a good movie worth watching

[vegasjames]

Here is one you may find interesting.  This is a jasper fulgurite.

[knifegirl]

Now that is cool beans!!! I have got to get a photo of a recent find by one of my friends. We were just talking about that it was from a strike! Thanks for posting all those photos and sharing info. Really interesting!

[1dave]

Repaired

[captbob]

Folks from University of Florida dug up one that was 17 feet long awhile back. Think that was the record.

news.ufl.edu/archive/1997/05/experts-from-uf-dig-up-worlds-longest-solidified-lightning-bolt.php