Quartz, chalcedony, chert, jasper and agate: the differences between them!

[@reginaldwelkin]

This explains a few things that most videos skip. I like how you show rocks you found, and don't just show cut purchased pieces from other places.

[@michaelbeck3576]

Great video other than the jasper explanation. Jasper is of any color it is an opaque chalcedony with impurities other than silica up to 40 percent. Thanks for the video.

[@notinmanitou]

Thanks for pointing that out Michael.

[@GeogJenn]

This was so helpful! Thank you so much for taking the time to put these together for us.

[@prospectorpaul1]

Great explanations, really appreciated! You did a great job breaking it down to Layman's terms, not an easy thing to do, thanks again

[@mundodaspedraspreciosas]

Very well explained the differences between agate and chalcedony. A hug and good luck.

[@jackieaudsley6787]

This was exactly what I needed, thanks for showing the differences and similarities!

[@angelinaabarca9701]

Appreciate your knowledge , THANKS FOR SHARING

[@kadoj]

I kindof have to point something out, my apologies. Jasper is definitely not just red chalcedony. I was taught that carnelian and sard (sard is darker in color) are translucent/semitranslucent agate/chalcedony colored with iron oxide, producing what you’re describing, more or less. But it can also be yellow, orange, whitish, even to the point of being confusable with some highly included citrine river pebbles. Jasper is mostly opaque, or only slightly translucent impure silica, and it can be red, yellow, orange, green, or even blue in some very rare cases. So yeah, thought I’d point that out. The line between the two is pretty blurred, but the best I can tell,

[@justincosby2258]

The difference though between carnelian and jasper would be opaque vs translucent though. If what you have is translucent it would be carneliam or reddish orangish or yellowish chalcedony if opaque would be a jasper or chert. The harder ones to actually differentiate between are jasper vs chert.

[@kadoj]

@@justincosby2258 that is indeed true, with the jasper/red-orange-yellow chert. Although, red chert is often easily identifiable because of the dullish red brick-like appearance that jasper usually lacks, being more vibrant and having much more of a luster to it when smooth or polished… then there’s metachert being an almost indistinguishable lookalike for chalcedony as well, and… well y’know, screw it, I’ll just skip to the end and throw it out there: silicate-based and quartzite-adjacent semiprecious and ornamental stones are very often poorly identified and confusingly categorized as a result of all of them looking at least a little (if not completely a dead-ringer) for everything else. Lol.

[@annedelainwclark7733]

@@kadoj I LOVE this comment! And once again it all feels as clear as jasper, or is that chert, or maybe just mudstone :-) - BTW I think I have some claystone that looks a LOT like chert with NO luster (is it possible for claystone to have dendrites in it?) This rock ID thing is HARD 😕 maybe 9 on the Mohs scale 🙂

[@jimmymcgill2557]

@@kadojyour absolutely right i was about to comment this but you already had, the first and last of the Agates he shows are definately Carnelian and Jasper comes in so many colours and patterns, so much so that you couldn't even list them all, i've found some that i've never been able to find a similar match online but is 100% Jasper, mostly if they cross colour i just refer to them as a type of 'Brecciated Jasper' and also not all Agates have banding, some have that lovely toffee colour with some quartz striations running through (sort of like frosted glass) and/or also feature small pockets with druzy crystals in! i think it's just because in the US especially in States like Oregon, Michigan etc that because they'res such an abundance of the gorgeous banded Agates and Red Jasper that they have there own opinion on classification of what makes what, i saw a video recently of someone in Michigan finding an Agate with purple colouring and they referred to it as Amethyst which is really not the case! but that aside this guy is awesome and i've learned so much watching his videos 👍🏻

[@jimmymcgill2557]

@@annedelainwclark7733you've probably come across a rock like Quartzite or maybe even a nice looking piece of Shale! even chert will have some sort of luster to it and be very smooth! 😊 also did you mean to say a hardness of 7?..all Quartz and Chalcdeony like Jasper won't be more than that, the only thing harder than a 7 is Topaz, Beryl and then the only 9 is Corundum (Ruby & Sapphire)

[@kgeitzel3293]

Excellent video. Thank you. Could listen to you talk about this all day

[@Makinplans1]

I love this video so much! I live next to a river and have buckets of all these rocks. Now I know exactly what’s what. You are a great teacher thank you very much! Happy hunting 💞

[@passiononfire]

Bro I value your content more than you even know. You're down to earth, relatable, walking around your house with your shoes off my kind of guy. I appreciate you and I hope you get more followers on here if that is your desire! Keep rocking out my friend!

[@rhondakelly8410]

Thank you for explaining so simply. It is much appreciated!

[@RockHoundQuest]

Thank you for the in depth explanation.

[@laurischlierman]

Definitely helpful! This is the first explanation that my brain could actually make sense of. Thanks!

[@Yorkia711]

Thank you so much your the first one to make real sense.

[@jacquineilson7085]

This us brilliant, as I am totally new to rockhounding, but hooked on looking for rocks. Thank you for this, really good

[@openyoureyes7539]

Learn something new every day. Thanks!

[@jennifershipp2599]

Thank yoy. I love learning about the differences and how to determine what is what.

[@VoytenTechnologies]

Thank you! Love the cabinet of wonders!

[@iraneman1668]

Great info here to inspire interest for farther study, deeper into an amazing world of the gems.

[@pamelapilling6996]

Thank you for the chemistry behind the difference.

[@jimknarr]

You have been filling the gap on the some of the most asked questions on the rock hounding forums. Great job! Which state are you located in?

[@CraigMcClarren]

I'm in MI and filming for the MI Rockhounds group! Glad you're finding these useful!

[@HoboMinerals]

Michigander love! Represent

[@jimv.661]

That was good. I subscribed. So...what's the difference between chalcedony and common white opal?

[@matias7700]

The one shown near the end which was described like candy corn really resembles Thomsonite, I think it has a bit of chatoyancy from the fibrous structure, agate or chalcedony doesnt normally have that effect

[@Anubis-hm7ro]

Perfect thank you

[@CplSkiUSMC]

Still learning... hey, are you one of those Michigooners??? I'm a reformed Michigooner myself, I live in Wyoming now and find some very nice specimens. There's another great Michigan rock hound channel... his name is Rob and I think he lives around Alpena somewhere. His channel is Michigan Rocks, check him out.

[@CraigMcClarren]

Yep, I love an hour south of Alpena. That area is fantastic for fossils!

[@CplSkiUSMC]

@@CraigMcClarren I graduated from Gladwin High School

[@adieaf61]

Excellent. Thank you.

[@PlouffePatrice]

the best explanation i`ve got so far.

[@Waltergoodboy]

Thanks....carnelian also will trip me up sometimes

[@stephenskidmore]

Thanks for the information. I am very curious about the honeycomb-looking fossil, because I have one just like it from the stream in front of my house in Southeastern KY.

[@livreservil]

Muito obrigado, gostei muito. Sua aula eliminou algumas dúvidas minhas. Agora tenho absoluta certeza que tenho algumas calcedônias maravilhosas! Estas que achei são lisas, lustrosas, cerosas, numa mistura leitosa de cores suaves, como um creme.

[@mackz964]

will you do the difference between chert and agatized wood and petrified wood

[@mackz964]

can you make one where you just show the rocks and compare them? visually seeing them side by side would really help me 😊

[@AndreasMueller]

This is so great! I still didn't entirely understand the distinction to Chert, though. Why is it a rock if it's cryptocrystalline quartz? And what are the crystalline structures? Also, similar question with rhyolite (which is also a rock). I've seen pieces of rhyolite sold that look like Jasper to me, and afaik Rhyolite is also largely cryptocrystalline quartz? Also, in most books I read, Jasper is a mineral which is a chalcedony, which is .. confusing given your definition.

[@alexhudson-]

You're the man!!! Best video ever!! Do you know if quartz is covalent or ionic bond??

[@bluegypsydoll]

This was wonderful! Thank you! 🎉

[@BubblePuppy.]

Very good thank you so much. I needed this explanation

[@mitchgillilan]

Great video. I was surprised you didn't mention the Concoidal fracture on cryptocrystaline quartz in identifying it.

[@justincosby2258]

Not necessarily helpful all cryptocrystaline will have choncoidal fracture but so too will quartz itself and I believe even quartzite. It definitely helps but is not alone a good identifier.

[@joeyripswell]

BooM RoasteD

[@moretimethanmoney8611]

One clarification from my years spent with chalcedony and "agates" is that agates have concentric banding as if formed around an initial droplet(s) of precipitate whereas onyx is a banded form of chalcedony that can occur in cracks and vents formed in other hard stuff at depth. Fun stuff.

[@jjcvmd]

Great video but can’t Jasper come in colors other than red?

[@billhardy7870]

Thank you for clearing up some questions I had, especially about Chert. I live in Western NY near Buffalo, between Lake Erie and Lake Ontario. While I have not explored ALL of those 2 lakes, I get so jealous when watching videos of others collecting all sorts of really neat rocks on beaches on the other 3 great lakes. The vast majority of water worn stones near me are mostly all from the Niagara Escarpment, broken off, ground down and rounded by the glaciers until about 10,000 years ago. So the beaches, gravel pits and such are composed mainly of limestones, sandstones and maybe a piece of shale that managed to not get obliterated on it's journey from the near north. Ocassionaly granite from Canada shows up and sometimes a quartz pebble, but it's mostly all sedimentary from the Escarpment. Still fascinating, but no agates, puddingstone or petrosky stones and such as found around Michigan and Superior. But we do have Chert. Lots of that formed in the limestone of the upper Escarpment and was shattered and brought south those thousands of years ago. I've seen chert tumbled and polished by some who collect it on Lakes Michigan, Huron and Superior but it's much more colorful than the black or gray we have here. My question is, will this black and gray Chert, which would be called Flint if it had formed in chalk cliffs.( or so I've read), tumble polish as well as the multi colored versions found on other Great Lakes? I haven't tried it as yet, as I received a rock tumbler in the mail just today! Thanks!

[@CraigMcClarren]

Awesome, I got my MS at SUNY UB and taught a semester for Buffalo State. I love that region!

[@canadiangemstones7636]

Chert will tumble nicely.

[@uscivilflag]

Didn't explain much I'm just as confused as before and jasper comes in many different color

[@mattw_1979]

Thank you 🙏

[@lindsaywang4413]

This is extremely helpful. Thank you for this video, you gained a sub

[@onepunch-nk4fs]

هل الصوان او الشرت عليه خطوط مستويه ام هي ميزة العقيق فقط

[@brik5hit]

Agate doesn't necessarily have to have banding to be an agate. Dendritic and moss are two examples of this...

[@travismorgan29]

So would all franciscan complex ribbon chert technically be jasper since it is an iron-rich red? I'm not sure I've heard anybody describe jasper so affirmatively but I like it. I've had such trouble determining what differentiates red chert from jasper but perhaps nothing?

[@davebraund1236]

Awesome video!!!! Thank you!!!

[@SPierre-dm4wo]

So where do dendritic/moss agates fit in, since they don't have banding? This is the first time I've heard of banding being a defining feature of agates and I'm confused...

[@Sharla1213]

Thank you! Third time watching this. Other videos have led me astray I think I’ve got it now.

[@Kya_the_camera_dog]

Thank you so much for making this video!!!! There seems to be a lot confusion on this topic. I do have a question, does the amount of moganite vary?

[@japhykeisers6711]

Good information in this video. The problem with agate, chert, jasper...is that their names where given (by romans, persians, stone-age people...)long before sience understood what they where and how they where formed by nature. Jasper and chert look (and are) almost the same but are formed differently: it is a recent discovery that chert is formed from the (compressed) remains of diatoms. Jasper is formed when clay-sediment is trapped in a layer of lava (simple explanation). In prehistoric times jasper was not as usefull like flint: no sharp edges, and agate is more brittle so chert used to be more precious. Later chert became less usefull and jasper and agates became more precious than flint or chert for ornamental use. Those days a lot of (semi-precious) stones where given the name jasper ('jaspis' in some other languages, just compare it to 'lapis', the Greek name for stone) Then talk about chalcedony: normaly it's about any type of micro- or cryptocristaline form of quartz,... except roze -quartz or opal or petrified wood or... and so on...(not talking about moganite because the name chalcedony is way older than the discovery of that hidden mineral) It is a mess, like most of the names given to minerals. They are mostly trade names and traders give the name they like best: ocean jasper is a tranlucent jasper??? Blue lace chalcedony IS banded!!! a lot of agates are hardly translucent because of the impurities or inclusions. To make things worse: jasper, opal, and agate can all be together in one piece of rock! Nature is to diverse to give it a few simple names. Compare it to 'rock' (the music). Is it rock because it contains electric guitars??? Is heavy metal the same as hard rock??? Mostly trade names that remained in use (slightly altered) after better understanding the laws of nature.

[@ednarodriguez7452]

Greetings, I have a stone and I would like to know what type of stone it is. can i send you photo?

[@olmilfishrock]

Great video!! Thanks for help with something I hav been having a hard time understanding. I have a question about Chalcedony, agate , chert and jasper. Since they are all very closely related ( microcrystalline quartz) is that why they all polish up nice ?? Thanks for taking the time to make these videos and sharing them with the rest of us! Keep rockin!!👍😎

[@Keriousity]

5:15 ohhhh that makes sense!

[@ErnestormExplores]

But what about moss agates ?

[@janellemuravski1285]

Thank you that was very helpful. Appreciate it

[@vincentcartalaba774]

Good day.Sir can you identify my stone please.thanks...

[@BlacksheepUntilIdieNowarta]

I have some very interesting pieces I’ve recently acquired and a I’m talking many varieties and quantities. I think you would find very interesting. I would like to show you some and get your thoughts I’m in S.E.MI. Also just south from A2.

[@Jademd83]

I'd love for you to take a look at all the chert I have down here in Southern IN! My collection is of all the things you have been naming. I think I may be finding a lot of this cryptocrystalline. Wish somebody could separate it all and tell me what goes where. Most pieces I know but then there's some that really trip me up and I can't ever get an ID online on them either. There's some weird stuff out there!lol

[@thomasgronek6469]

great video, thanks. You picked up a new subscriber. What is translucent Arkansas stone (whetstone) ? I it banded chalcedony ? How does it differ from novaculite ? Sorry for the stupid questions, this is Geo 001 for me.

[@davidbarnett5777]

How do you differentiate agate from carnelian?

[@mamaboomer3707]

My son found a wierd heavy beautiful rock about 150lbs my husband broke it open with a 30lbs weight and it has crystals in it...would love to get in contact to see if u could help us identify it

[@ayselgokcenaysek4248]

Bu taşlardan da Türkiye'den alıyor musunuz bende çok var size nasıl ulaşabilirim

[@MyAnniepie]

I love you dude, so cutely scientific. I’m preparing to help my 5 yr old great grandson become the rock hound he was born to be, he loves rocks, like me😊

[@billatnip6425]

Take him out with you best times and education .

[@julienaklei]

So is chalcedony a silicate? It is listed in wikipedia as an oxide but it also says it is a type of quartz so I am very confused. Which of the mineral groups does it belong to or is it a mineraloid?

[@passionflower13]

I'd love to send you some specimens 🥰 I find all kinds of cool stuff here in Virginia 💙

[@justjoe942]

Thank you.

[@matthewholmes9261]

Great video, thanks Craig! Love the 'Cabinet of Wonders'! :) Just two questions, how do you know if you've got chert or just a big piece of chalcedony if both are cryptocrystalline quartz? and lastly, where does flint come in to all this? Keep up the good work!

[@CraigMcClarren]

Chalcedony is usually, but not always a bit more translucent and often a bit waxier. The key is that chalcedony occurs as a mineral in other rocks while chert is a standalone rock (though it does form nodules in other rocks, so it can certainly be tricky!). Flint is a variety of chert!

[@jimmymcgill2557]

i know this is an old comment but i just wanted to add that Flint is almost always a dull grey colour! and Chert tends to have a a lot less of a luster/shine than Jasper and is also much less 'smoother' to the eye and touch 👍🏻😬

[@jimmymcgill2557]

@@CraigMcClarreni've watched almost all your videos and tour by far the most easiest to understand the way you go about your videos! thank you for the all the great content! and your little boy Jerry is adorable! 👍🏻

[@rosemaryspringer4239]

This was great!

[@captainflint89]

true jasper forms in igneous rock where chert forms in limestone and chalk , jasper occurs in the same environments as agates and chalcedony and often forms part of the same nodule , there are many colours of jasper and chert , some look very similar but one mostly forms in calcium /lime rocks and one volcanic . scottish bloodstone jasper is green with red specks for example , and the difference between flint and chert is that flint forms in chalk where chert forms in limestone . there is chalcedonic / agatised and opalised flint and chert but never the other way round . then there is the imposters which are fine grained mudstone, siltstones which have been silicified or otherwise undergone a geological process that makes them "flinty" in texture

[@brianmaney1973]

I enjoyed your video, face value!!!

[@tasckadn446]

Muh teşem bilgiler teşekkürler❤

[@justincosby2258]

Very nice video I found it through a rock and mineral group I follow on fb. Just a couple of things though. I would also include an explanation of plume and dendritic agate or agates with inclusions that dont necessarily have banding into that definition of an agate, I dont know if that is technically correct but it is so commonly accepted that I believe if it isnt it should be. I would also give a brief explanation of flint as it also fits into the same category. And while it doesnt exactly fit into the same category I would also give an explanation of common opal and opal displaying play of color because of the close relation to the others. Then you could also touch on exactly what a geode is and a thunder egg and the differences associated with those. Not trying to bash you video it was excellent and gave great and accurate definitions. Just felt it could have been a bit more detailed with those regards to clear up any left over confusion amongst people. Thank you very much I loved it.

[@duhduhvesta]

Is chert just diatoms because I thought they evolved in the Jurassic (200 million years ago). Does this mean chert only formed after their arrival!

[@mrfxm55]

The basic keys to identification is usually hardness and streak color. Hardness is the easiest indicator when you're outside hunting. The basic knife blade hardness 5 on the mohs hardness scale is a good tool but a steel nail will also work. Most rocks are quartz. These occupy 86% of the Earth's crust. If your knife blade can't cut into it it's likely quartz 6-6.5 on the mohs hardness scale.

[@justincosby2258]

No the most rocks are quartz statement is nowhere near accurate or the 86% comment. Quartx itself isnt even a rock its a mineral and if Im not mistaken the most common mineral in the Earths crust I believe is actually feldspar of which I am almost certain there is at least the widest variety of. I could be wrong. But yeah no definitely not 86% quartz in the crust.

[@waynekirk9942]

Great content! Please work towards better audio.

[@johnsykesiii1629]

That dark green "agate" is called "prase". It is actually more related to, and occurs with, jasper. An apple green translucent chalcedony is called "chrysoprase" See "Dana's Manual of Minerology, 18th Ed."

[@virginiarocks]

Thanks. This was very helpful (even in Virginia). 🤓

[@judithwalker3600]

the audio is so low I can't even watch it! bummer

[@amazingalannah]

I like your map tho. Ima map nerd myself. I haol N to have that one in my phone or something similar at least.

[@thomasgronek6469]

Why SiO4? Si has four bonding sites, and oxygen has two bonding sites. Two oxygen have four bonding sites, that's why it is SiO2, NOT SiO4 What am I missing?

[@duhduhvesta]

I kinda don’t get quartz & chaldoncy

[@janetkelly4280]

Lol complicated chemistry...good God and thank you for your education share time

[@onepunch-nk4fs]

اتمنى كتابة الترجمه اسفل الفيديو. مع وضع ميزه ترجمه الفيديو

[@geoffgeoff143]

While not a mineral, you missed opal

[@teamgladeon]

I have one

[@donkeyrokman]

There's a whole lot of oversimplification going on here, once you get past the chemistry.

[@ElectricUniverseEyes]

🤜🏼⚡️🤛🏻

[@jimmyc3238]

0:52 Your "explanation" of chemical bonding, structure, and stoichiometry is incorrect and so bad I don't even know where to begin. Better just stick with lapidary work.

[@bjellison905]

Wheres your video?

[@debzyj376]

Thank you…. Enjoyed!

[@Keriousity]

Lol 😂 I am going to watch it again... I am such a nerd

[@retrothink]

Sedimentary rock has always compacted by pressure solution of quartz: Proposed Method for Shale Compaction Kinetics", 2021.

[@christopherort3045]

Cool

[@retrothink]

(Google the reference below)

[@ZaileRupin]

I have a chalcedony

[@brianmaney1973]

Confusing the issue by comparison... Show each formation by itself, rather than "VS".... I know YOU know what you're saying, but for people wanting to learn, just show the crystallline comp for each mineral. How they interplay and how they're formed is infinitely more intricate, and random, sometimes.

[@konasteph]

lots of stone age tools were made from Chert.

[@geoffgeoff143]

I disagree with a lot of your information. Jasper is chert with clay inclusions. Flint is chert formed in chalk deposits. Chalcedony is often clear. Chert and chalcedony are very close. However they have different crystalite structure. Agate is banded or varigated chalcedony. I suggest you read the late Terry Moxon's book. Chert is a rock. Agate is a rock. A rock must contain more than one mineral. Jasper is a rock. Opal is not a mineral as it is amorphous.

[@enriquecastellanos7110]

Your audio is not very good . . .