Is it slag? How to tell the difference between obsidian and slag glass.
Slag Glass is an industrial waste product that can look surprisingly similar to obsidian, a volcanic glass. Without knowing important and often minor differences they can be easily mistaken for one another. On this episode of Rock Talk we discuss how slag and obsidian are similar, how they are different and how YOU can tell the difference when out rock hunting!
Пікірлер: 178
This is the angriest I've seen any man ever be about rocks. It is contagious. Now I, too, am outraged by slag.
@hunting_vr1514
6 ай бұрын
As a rock hounding child in MI I feel that. It's all slag. However, I collect the heck out of slag and I love it and have so many colors.
Think how people feel when they realize they have spent thousands of dollars for a slag glass called Andara. Yes it is beautiful glass. It makes me mad though that people are making a lot of money tricking people. I do love Obsidian and just ordered my first piece, a pendant. I am so happy to have found your rock channel. Way to go.
I have recently been fieldwalking in an area that has had multiple settlements over the last 8000 years. I have found obsidian blades as well as lumps of black, glass-like rock. At first I thought it must have been unworked obsidian but thanks to your video, I now know it was slag glass, likely from the medieval period.
Sorry to say, but you are very wrong about not being able to see the light thru slag glass. My jewelry making business depends on it.I have been collecting slag for years and making jewelry from select pieces that you can shine a light thru. If you'd like, I can send pics.
@-_--lj6qo
3 жыл бұрын
can confirm my grandmother worked at a glass plant and used to bring stuff home
@pressinpickle345
6 ай бұрын
Does green slag glass have black flakes in it?
@JulianaAndersson
2 ай бұрын
Maybe they are actually pieces of obsidian… ? Idk… 🤷🏼♀️ Glasses made at a glass factory are different from by product glass chemically made from foundries… ?
I have a piece that matches every description of green obsidian, except it has small visible bubbles on the inside. I read that sometimes bubbles visible to the naked eye can be trapped in lava flow, during crystallization. Mine is completely transparent and nearly translucent. I also read that the inclusions that cause the thin flowing bands, in green obsidian, can cause its green color. Moreover, in my research, I read that those trapped bubbles can cause its green color. Is there a way I can send you pictures or videos to examine? I'm completely devastated, as you said. It matches every description I've read, including lythiophysae.
The best, concrete info about slag versus obsidian I have seen! I never have heard about the transparency test anywhere before... and this was uploaded only a few days before I needed that info! Take a like and a sub :)
@paydenvietmeier9526
2 жыл бұрын
I have a very thin slag piece that is very transparent but definitely slag as i live in Pittsburgh.
@arkoffire7-7-7
Жыл бұрын
I have transparent thin slag glass also found near an iron forge.
@trulahudelson8118
9 ай бұрын
I second this!
@lindacondray7918
6 ай бұрын
I’m a glass artist who works with slag glass. IT CAN BE CLEAR or solid WITH CLEAR areas. Don’t use clarity as a defining characteristic.
I was gifted a large piece of red stone that my Uncle said came from a volcano in Maui, someone said it's slag but the inside was chipped and it looks just like black volcano stone. It has the clear spots like you say about it being obsidian when you hold it up to the light. It doesn't have dirt or anything under it. No bubbles either.
I live in Ohio and kayak along the Ohio river for arrowheads and native artifacts. I’m just now getting into geology. I found a ton of slag glass that is black with tiny golden veins. Looks beautiful. Makes sense with all the steel making that happened in the region
Thank you for the information! Me and my kids, ages 7 & 10, are getting into rock hounding in Arkansas. Subscribed!!!
I've been trying to figure out these pieces of rock I found for way to long but you did it sir! Thank you thank you thank you!!!
I wish I could find more rock lovers in my area. Its nice to hear people who share the same passions for rocks. Rocks are soooooooo cool! I found a piece of green blue slag rock while visiting South Carolina. I didn't know what it was, but I knew it had been liquid because of the bubbles, and it was such a unique color!
Thanks for the show perfect done man !!!
🤣 Your excitement and enthusiasm is awesome dude...keep it up! 🤘😎
Thank you for this! I did not question if I had obsidian. But I have "bog iron", hematite, limonite, pyrites with large black crystals in them once you split them open. pieces poke out the large balls. There are smaller pieces with smaller ones. The black glass has copper gold shimmer through a loupe- but also tiny circles. It is beautiful in the hematite and limonite. Found on Western shore of the Chesapeake bay I went back and got more they are so beautiful inside! And its so fun to split them and see whats in there!
That was incredibly helpful. Thankyou! 🙂
I found some slag today think produced from explosions? It's see-through in the light and beautiful shades of green Grey and blue Grey. I have some brighter green peices as well that you can't see through as well as a purple peice. Found in PA. I thoroughly enjoyed this video. You're so right about the excitement I did not expect to find this today. There was an incredible amount of rose quarts as well but with so much slag glass the rose quarts didn't seem as special. Can't wait to get back out there!!!
Nice chunk of Leland blue. I have A LOT of slag in my local area from an 1800s smelting furnace.
Awesome video, informative and interesting.
This man would love ark...
@craklin
3 жыл бұрын
Indeed ark sounds like a amazing game for him, including the primal plus mod whould be even better.
I watch your videos from Spain and I like them a lot, I know you will have more suscribes in the future🙌
Think you'll upload more cool rock stuff in the future?
brilliant video - this has really helped me thankyou. subscribed!
I live in the Connecticut valley in Western Mass. My son found a rock in the local river that floats, and without really thinking it through, I told him it was probably some type of volcanic cinder. I'm originally from Hawaii and the rock my son found looks like the volcanic cinder I am familiar with. I now think I gave him bad information and it's probably slag. He is really excited about having a volcanic rock and carries it with him during the day and puts on his night stand next to him when he goes to bed. I want to figure the mystery out for sure before I tell him what it really is. This quest has led me to a lot of really interesting research on the geology and prehistoric history of my area, but it has not helped me identify my son's rock. Thank you for the information. I think I will check out the Reddit link.
Awesome video dude.
Very cool! I make jewelry, and this is so helpful. Thank you!
Thank you ! Very helpful
Found your video really helpful, thank you. Im very sure now that my finds are just slag glass. However, light can pass through some of them? Could that be possible?
Great informative video
Flint Knappers will buy all that slag glass you can get,it makes beautiful arrowheads,knives and spear points and it's hard for us to find to buy.I just checked out ebay and prices are rediculous when you can buy obsidian for 2 bucks a pound.
I've read that what makes obsidian isn't the fast cooling but the lack of water in the flow. The evidence was the Big Obsidian Flow in the Newberry Caldera in central Oregon. The size of the flow is such that it would have taken some time for it to cool yet it is obsidian clear through. Obsidian is chemically the same as pumice without water that causes the frothing. You can find in the flow obsidian that has some frothing similar if not the same as scoria. Thanks for solving a mystery for me, I have some of the opaque green glass you showed that I got in an estate sale. I knew it wasn't obsidian but didn't know was it was
You mentioned that you’d be willing to help folks identify some rocks. How do u receive pictures?
Thank you for this video, it just helped me solve a mystery that's been bugging me for over a year. I found a few pieces of what I thought was obsidian on a beach, but there are no volcanoes around, whatsoever. I had never heard of slag glass before, so the only conclusion to me was obsidian. But seeing this video, it's for sure slag glass. I'm a little disappointed its not obsidian, but slag glass is still a neat find also :)
Very often I used to find slag from antiquity and even older, over 2000 years old, and it is completely identical in 50% of cases to black obsidian. With this slag, some specimens are enriched with inclusions of peridot, which is full of sparkling dots, like yellow-green opal or zincite. This slag must have the same value as zincite crystals, which are actually the same slag in the zinc production process. These beautiful pieces must be officially valued and have a price like obsidian or even more.
I have obsidian collected from Northern California which has very visible air bubbles in it. Would be happy to send you photos of it and exactly where it was collected
Howsit Rockah!🤘 I found some glassy stuff in the field and wondering, can the production of slag glass also produce pumice?
I came across a 20lb chunk of green rock & I got real excited ! Mainly due to slight dark veins running through it on one corner.....but....it does have a few bubbles in it, so I guess I cant start dreaming of a new car now 😂😂 I've learned something today though, so thank you 😁
I was in a local farm field today metal detecting and it detected a piece of slag. Detector went crazy. First time finding it.
What about bulk slag glass? This appears to be transparent. I found some interesting pieces of slag/obsidian that I can't really identify. It's dark green and translucent on the edges as u told in the video. Some places are more brownish colored but not often.
I have a black rock, glassy shattered like like. I found it in northern arizona In a meadow next to the mountains. It was a on a pile on the ground and not next to any industrial factories or facilities but some rural homesteads. No bubbles and it is jet black. But when I shine a light it shows some hidden brown. Also, this rock is rather thick so when i shine the light i dont know if its the light spilling over or if its see through. Is this rock obsidian or slag?
Awww. I knew it was more likely that I’d win the lottery than find obsidian in the UK but I found a few pieces of basalt too, and with the place I found it being a footpath made from excavated materials to make way for a housing development, I thought I might have got lucky. There’s bubbles, bits of dirt and even iron/steel “bearings” in it. I can still knapp it though so happy days.
I live near an old furnace with a trail... ive been finding these black grayish glass pieces with bubble patterns everywhere. Could it be left over from the furnace? Hasn't been used in 50 years probably....but some of it is see through, so I'm confused.
I've been doing research on obsideon for a long while now and I've been finding rainbow obsideon and all the other colors and mine don't have holes and the edge can have light shine through them
Maybe you can help me. When excavating my house foundation, a boulder was removed with this clear glass like stuff embedded in it. Perfectly clear and has bubbles inside. Its odd
Is there a way to just make obsidian I want to try and see if I can make a form of something that I could possibly use for flintknapping, I live in the city so my options are very limited.
Now I'm in IL and we do have hicks dome in Southern IL. I also live right next to a river that runs to the Mississippi. Is it possible to find some a few yards away from the river? I can't tell if it's slag or obsidian 😂
I found a ton of blackish green glass rocks in the side of a deep cut riverbank by my house, some of these rocks are huge 3' across.. The rock/glass is indeed translucent and some have some bubbles you can see in them. The location is near an old windmill factory from the 1800s-1900s. And I am curious if this is all indeed slag or obsidian.. Every rock is translucent 100%. Slag can never be translucent? Or can it?
so what do you think of zincite, an industrial byproduct
I don't have volcanic activity here in Alabama ..the rock I have does not have slag properties in my opinion.. what do you think it could be?
Thanks. I was really unsure of what I had. Now I know. 100% slag glass.
Hi-I found what I thought was black slag glass(in the West Point area in NY), but how can you tell if it is actually anthracite coal?
Thank u so much!
I have green slag with black flakes in it when put over a light. I thought it was Williamsite but slag makes more sense. No one has been able to tell me why it has black flakes though.
thank you so much
Very informative :)
Slag glass seems kind of cool to find...
@lauraisenberg5180
3 жыл бұрын
You have read my mind lol i found these rocks that are killing me... i have done so much research, and i would love to share a pic or 2 with yoy
What about a black transparent one with bubbles, very light and not found close to an industrial waist deposit or volcanic activity?
Is it possible to find obsidian and slag In the same locations? I have found at least three 5 gallon buckets of blue glass. I've found way more than that of the green, purple, Grey and even some brown. Of all shades
The Primal season 2 promo is out!!!!!!!!!!!!!!!!!!!!!!! I'm so freaking excited yes yes yes Fang is back
Is there a difference between slag from coal manufacture and other industrial processes ie steal... son found a pretty black shiny oval rock that shines red when light passes through it. I assumed it must be slag as live in a mining area in Wales UK.
What about if it’s from a glass works? It’s been called slag glass that I have a whole collection that we have pulled from the river near me that had an old glass works. They do have some opacity, we know it’s glass because it’s in huge piles, you can see light through it.
i have a black piece on my desk which up to the light it give it a glassy green transparency so im unsure whether its just a big hunk of beer beer bottle glass or if its obsidian? p.s i found it in a field in England
think what I found is slag on the river bank but the good news is being a railfan did get nice video of train crosing that trestle next to my find so that one made my day
So, I have this piece of what I thought is obsidian, when I put light through it, it looks to be a green-yellow color. I wish I could send a pic through here
@racheleldridge4046
3 жыл бұрын
I have the same thing! Did you find out what it is?
How about doing a video comparing obsidian and the different types of opal.
Amazing
30 yeas ago I went fossil hunting on a beach near Parksville BC Canada and found, on the graveled sand surface in plain sight a charcoal black well worn and rounded 2 inch rock (likely from being buried in the shifting sea soaked beach sand for untold time) with a recent broken end of black shiny circular obsidian like fractures and light could shine through it with a clean dark golden greenish colour quite likely broken by a previous fossil hunter then discarded it before I encountered it . The area was a popular beach area with scenic hills, cliffs and forests and the black rock was at the back edge of the beach on top of the coarse sand. Recently It was confirmed to be obsidian by a local archeologist after showing it. I would think that rock is an ancient human sourced artifact possibly centuries even thousands of years ago . Im sure that beach area was as popular a place for ancient native peoples as it is for the present local public and tourists alike. Obsidian was a highly valued commodity among many ancient native tribes and is not sourced in my area, it likely was traded and traveled hundreds or thousands of miles by foot and canoe from the mainland to reach my area.
Thanks for this, I've been scratching my head over some big-ass chunks I found lately (1000 miles from the nearest volcano, but 100 yards from the old foundry!)
@BeRNGaming-wn4iw
18 күн бұрын
He's wrong though about Slag
@jamesdixon5714
18 күн бұрын
@@BeRNGaming-wn4iw well I guess I've got 4 fist-sized chunks of miracle obsidian, then. BRB gotta go shove them waaaay up my ass to gain their powers.
do you know anything about Andara ?
Can you please hell me with my identification of this rock ? Idk if it’s slag glass at all bc light is seen thru the rock and there are no swirls of white or other colors try it .
I love it your videos
My stuff has round bubbles in it but can shine a lot of light through
The piece i found has a trait from both obsidian and slag and im confused The edges let light through but there is just one air bubble (its more oval) on one side of it
I found some really black crystal in the side the beach. Looks like obsidian, but no Vulcan here in Massachusetts
Ok whats the difference between slag glass and black mica?
Dude, you rock! xD
for opaque edges it depends on the slag. i got a bunch of it from pine grove furnace here in pa and many of the glassy glassy pieces will glow under the sun and with a flashlight most of the glassy and glassy glassy pieces will glow or light up depending on whats in it and whatnot, there are many like what you show at 7:48 too. a good chuck of what we got, at least from the spot we got it from looks blue, nice and swirly with whites and varying shades of blue but actually glow/light up green. some are purple or cloudy gray. we also have a few pieces of both the opaque glass and solid glass with the cooled pour lines on them from when it was dumped out.
Nice video, but how can you tell if its real obsidian if you buy it over the internet, and how much does it weight to ther dimensions, is ther a video about that available? 🤔
I have a piece that's still questionable after watching this! I'm fairly certain it's slag, but you can see through the edges of the fragments, I can't detect bubbles within it, and it has conchoidal fractures. It was at least a 10lbs piece I found, and it cracked the other day. The interior is irridescent.
@lenidubelinc000
Жыл бұрын
Same! The one I received for a present, it checks all the boxes for obsidian. Does the inside of yours look like black volcano stone? Like black volcano too, along with being iridescent?
Mine is translucent. Found in a creek in East TN.
Yey, regarding point 2, i have a tremendous amount of transparent slag. So you should probably edit that point out. Love the vid though, subscribed.
lol..., when speaking of finding that blue piece of glass....WOW...!!! So we recently found a beautiful place loaded with slag..., one of the first ones we found was this crystal green and purple slag glass rocks both together poking out of ground like 2 huge emeralds and amethyst ...psss... this is before we knew it was slag...talk about thinking you found a mother load HOPE DIAMOND or so we thought lol...thanks for video love it. sincerely'N'TRUTH: d'Anthony
I have slag I wanna seal it if possible
I think I found slag.. but it's slightly magnetic with gold, silver, and rainbow inclusions. Maybe hematite with magnetite? I'm still stumped.
second also love ur content bro
@RockTalk
3 жыл бұрын
Thanks Matthew!
found so much slag glass wile back at the time was thinking I hit the jack pot in to found out there was A still mill here one time
I love your video you are amazing at explaining my type of language lol
Great info, but there are slags that do have some translucency. Leland Blue is a great example of that.
I have like that,but if i put light on it ,it turns yellow
Hi, I am from Mexico
Serendebite vs obsidian difference?
Thank you so much for this helpful information! I’m a little disappointed my mound of obsidian I thought I fumbled upon was in fact flag 😂 Oh well! I’m glad to know the truth!
Someone who gets it 😍 I'm such a rock hound. Thanks for this video..just came across obsidian! 🤔 Or is it slag? 😩
this was actually helpful, well mine can pass light at the edge so it must be obsidian.
Thank you! I thought I found some amazing obsidian, but it’s slag 😣 still cool, though!
Was your brother on Naked & afraid
How come you stopped uploading
not all slag is opague!!! i have a piece thats 100% slag but light passes on the edges
@upnorthadventureswithccc
2 жыл бұрын
I also have slag that lets light in on the edges !
[0:52] 100% is my old collection that someone stole from me, I reconize evey stone. I was told it's klinker but if it's not I can go grab a truck load of it. All 11 of them rocks came from the same spot in a 30 foot radios. I keeped them in a navada shoebox that was redish in color. I wonder if they were still in the shoebox when the next person got them.
@Ro-Bucks
Жыл бұрын
100% my collection was slag, I'm going this summer to collect more cause slag or not it still looks cool
More episodes of primal btw they are awesome you must watch them
Don't know how to put a picture of it on this board.