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Flint in north america[edit]

Flint occurs quite often in North America. Do we have a source for that comment?

Do we need one? The American indians seemed to have little trouble finding it - 90 percent of their arrowheads are flint, at least in the northeast US. I used to live near the Onandaga limestone outcrop, and flint was as hard to find as sand at the beach. PAR 15:46, 4 November 2006 (UTC)

There is a park in Ohio, near Neward, called Flint Ridge where american indians mined flint. The pits are still in existence. I'm also aware of Indians mining flint in Wisconson, but don't know the exact site. A link to an Ohio website on this follows:


In the explanation of how it works, the steel is burning, but I know different. Try heating flint from a lighter with another lighter. Throw it down on concrete. No steel, yet it burns, so the flint is burning by itself. Perhaps it is incompletely oxidized Silica. IOW, Si2+ becomes Si4+. I had speculated that it was Iron Phosphide. Thanks for filling me in. I wonder if Iron stabilizes flint. 11:07, 24 May 2007 (UTC)

Modern "flints" aren't flint. They are Ferrocerium. The flint/steel roles are reversed. True flint (from the ground) doesn't burn, Ferrocerium does. -- 21:41, 27 August 2007 (UTC) —Preceding unsigned comment added by (talk)
When flint is struck against flint it still produces a spark. -- 00:56, 10 September 2007 (UTC)
I agree, all you need to do is throw a flint pebble on brighton beach at night to prove that it sparks. 23:24, 4 November 2007 (UTC)
I found the answer to this mystery. Numerous minerals including flintstone and quartz exhibit a phenomenon called triboluminescence. When subjected to friction, a part of the crystal temporarily decomposes chemically, and, upon recombining, emits visible light. For quartz, e.g., the emission spectrum resembles that of blackbody radiation at 2800K, which is similar to the actual temperature of real sparks from ferrocerium (source). Therefore, triboluminescent little splinters from such a mineral look much the same as real sparks (except being less bright). However, they are barely warmer than the environment and cannot start a fire under realistic circumstances. So much for the "sparks", but can flint explode?
Well, rocks can and sometimes do actually explode when heated by a campfire. Rock, especially but not only porous rock, can contain water that forms steam when heated. If the steam cannot escape quickly enough, the steam pressure can suffice to crack or split the rock, or in rare cases make it explode. However, on the Internet, one can find reports not only of exploding flintstone, but also sandstone, limestone, basalt, granite, concrete and more. Uneven heating can also create tension in a rigid material that can cause it to explode in the worst case. A well-known example for this phenomenon is glass (though it typically only cracks harmlessly). The bottom line is that I suggest removing the warning from this article. Instead, a warning, not specific to flint, may be included in the campfire article where it is more appropriate (which already contains a warning against lighting campfires directly on rock), if anyone finds reliable sources for a particular set of recommendations. Aragorn2 (talk) 15:49, 17 March 2010 (UTC)
I'm doubtful of the exploding flintstone story, too. As you said, modern lighers don't contain flintstone, instead, there is a spring that pushes a thin ferrocerium rod against the "rasp" at the center of the steel wheel. The spring is used to ensure that the rod has contact with the wheel even as it becomes shorter from wear. Heating a ferrocerium rod and throwing it against a hard surface has the described effect. Ferrocerium from lighters is colloquially called flint or even flintstone. To me it seems very plausible that whoever came up with this warning was confused about the various meanings of the word. As for the flint against flint anecdotes… I'm not sure, but friction heat alone might accomplish this as the edges of flintstone can be very sharp. Aragorn2 (talk) 23:13, 6 March 2010 (UTC)


Anyone noticed that the image of the flint walling in england is on it's side? no-one ever lays flint, or brick for that matter, vertically. 23:24, 4 November 2007 (UTC)

Yes, this image is clearly wrong (rotated). Who's gonna fix it? Traveller palm (talk) 16:16, 28 May 2009 (UTC)

Excuse me, but the image of flint from Onondaga looks very much like obsidian to me. -- (talk) 19:49, 8 May 2009 (UTC)

  • It does look like obsidian, but I think that it's just the lighting in the photograph. Perhaps though it would be more clear to use another photo of a flint sample that's more easily distinguished from obsidian. --O crandell (talk) 01:33, 5 December 2011 (UTC)
  • Why was the image changed back to the Onondaga photo? The photo is not a good example for a few reasons. First of all, from the lighting, it looks like obsidian. Second of all, "Onondaga Flint" isn't actually a true flint. It is only a "flint" in name. Its parent rock is neither chalk nor from the Upper Cretaceous. It is frequently even referred to as "Onondaga Chert". The argument presented for the change was that this photo is "a better representation of choncoidal fracture and prevent confusion with opal". This photo does not clearly illustrate how a concoidal fracture should look as the surfaces have many small fracture faces. And what about the confusion with opal? Opal also fractures concoidally. AND opal often has a glassy luster - much like the current photo of Onondaga "flint". If there is no better reason for using the current Onondaga photo, I'll change it after a few days - either to the previous Miorcani flint photo, or another flint photo. --O crandell (talk) 12:00, 23 February 2012 (UTC)

The picture of Miorcani flint shows a piece of flint from a flint mine. It's not a hand axe. I collected it myself. It was a nodule and I broke the cortex off to expose the inner (flint) material and show the typical conchoidal fracturing. It might look like an axe but it's not. I reverted the comment that someone made that it's an axe. — Preceding unsigned comment added by O crandell (talkcontribs) 12:44, 5 January 2013 (UTC)

Flint Composition[edit]

Last time I checked, flint wasn't a form of quartz. Where did they get this from? (talk) 16:41, 30 March 2008 (UTC)Lance Tyrell
Just added a couple references for you. Vsmith (talk) 19:03, 30 March 2008 (UTC)


Erroneous or not, the term "flint" is used by British potters (Hamer and Hamer, 2004), as well as American (Rhodes, 1969, reprinted). - Marshall46 (talk) 21:23, 9 July 2008 (UTC)

No the term is not used by British potters. However yet again the underlying flaw of Wikipedia is demonstrated: just because a reference can be found then it can be put into an entry irrespective of it being correct or not. (The Hamer & Hamer book is full of errors.) I have modified the article, not because the British use of "flint" is correct but because a reference has been found to this erroneous useage, and one which is not used in the UK (and if it is, it is both rare and incorrect) —Preceding unsigned comment added by (talk) 03:18, 10 July 2008 (UTC)
This is a discussion about words, not things, not about whether British potters use the material flint, but whether they use the word "flint" to describe a material they employ. They may use the word correctly, they may use it wrongly, but we are trying to find out whether or not they use the word. In order to do that, we simply have to find examples of its use. I have given one example. Here are two more: S.Murfitt, "The Glaze Book", Thames and Hudson, 2002, p.15 and M.Wondrausch "On Slipware", A&C Black, 2001, p.37. You might also like to check the online catalogues of Potclays and Potterycrafts, both of whom include a material which they describe as "flint". So I think that establishes the fact that the word is in common use among potters in Britain.
Incidentally, I would be interested to know what is the material that they erroneously describe as flint? It sounds as if you have some expertise there.
If you would like to become a regular contributor to Wikipedia, do think about creating a Wikipedia:User page. It's also helpful to other editors if you sign your contributions. Marshall46 (talk) 09:29, 10 July 2008 (UTC)
Having worked in the British Ceramics industry for many years I can assure you that both flint is no longer used and the use of the word for other fillers is exceptionally rare: I would saw unknown but occasional examples may be found. I also note that your finding of a couple of uses of the word (although no description of what the material is or when or how it is used has been given) can not support the claim of "facts" and "common." My edit, which you reverted, acknowledged there may still be some people who use this out of date terminology. I will modify the article to both reflect the use in the UK & US, and give supporting references.
  • "Flint is a microcrystalline variety of silica obtained chiefly from France and England ... It is prepared for use by calcination and grinding ... Flint is the term commonly used by the American ceramist to designate the raw material used to introduce free silica in glaze batches, irrespective of the mineralogical nature of the raw material." Ceramic Glazes. 3rd edition. Parmelee C. W. The Maple Press Company. 1973.
  • "Flint - odular chalcedonic silica from the chalk deposits of W Europe and elsewhere. These flint pebbles are calcined and ground for use in earthenware and tile bodies. In the USA the term 'flint' is often applied to other finely ground high-silica rocks used in whiteware manufacture." Dictionary of Ceramics. 3rd edition. Dodd A. The Institute of Materials. 1994.
  • ""Flint has traditionally been used in the UK ... Prior to milling flint is calcined" & "Manufacturers have now changed to quartz" & "Quartz from the Cheshire Plain and The Staffordshire Moorlands are extensively used by the UK whitewares industry." Changes & Developments Of Non-plastic Raw Materials. Sugden A. International Ceramics Issue 2 2001. —Preceding unsigned comment added by (talk) 16:30, 10 July 2008 (UTC)
You didn't use to edit under the name of Theriac, did you? Marshall46 (talk) 17:41, 10 July 2008 (UTC)
No, I didn't. Why do you ask? —Preceding unsigned comment added by (talk) 18:40, 10 July 2008 (UTC)

I have made this change: "the word 'flint' is now erroneously sometimes used". Wikipedia reports usage, it doesn't judge it. Marshall46 (talk) 09:27, 21 August 2008 (UTC)

Changing just the word erroneously made it harder to understand; hopefully what I changed it to helps. (talk) 04:09, 29 August 2008 (UTC)
I have simplified that sentence and removed "misused". How can a word be "misused"? If it is used in a particular way, that is the way it is used. Wikipedia reports usage, it doesn't judge it. Marshall46 (talk) 09:30, 12 September 2008 (UTC)
But you have corrupted what is given in the references, which is surely editorilizing and hence you are not reporting usage. The use of "flint" for quartz fillers is inaccurate to what flint is, and hence the subject of this article. Wording that is accurate to both the references and the useage needs to be chosen, and the latter includes that what some, almost exclusively US potters, call flint and which is not actually flint. —Preceding unsigned comment added by (talk) 09:14, 14 September 2008 (UTC)
I cannot understand your comment, but the point remains that potters in the English-speaking world still use the word "flint" for one of their materials and potters' suppliers still sell a product they call "flint". Marshall46 (talk) 11:05, 14 September 2008 (UTC)
My point was that your description was not accurate to the reference. The important fact is what some US potters call flint is not flint. And this usage is nearly exclusive to the US. Also, the English speaking world is very big and many of us know the difference between flint, quartz, cristobalite, tridymite, silica, calcined flint etc, etc. :-) —Preceding unsigned comment added by (talk) 19:31, 19 September 2008 (UTC)

Physical Characteristics[edit]

Nothing about it's chemical or physical properties? I know it is a hard substance, how does it compare to other things on the Mohs scale or whatever. What else about it is noteworthy? Lomacar (talk) 22:40, 19 April 2010 (UTC)

  • Flint (as are other forms of chert) is a rock, not a mineral. It's hardness and chemical properties can vary. BUT... since it's main component (usually over 95%, sometimes over 99%) is quartz, then you could generally say that it's hardness is 7 on the Mohs scale, 100 on the absolute scale, and chemically it's almost pure SiO2. Commonly it contains oxides and hydroxides of iron and/or calcium carbonate among many others. — Preceding unsigned comment added by O crandell (talkcontribs) 12:08, 23 February 2012 (UTC)

Needs additional disambiguation warning: "lighter flint"[edit]

Ferrocerium or "lighter flint", is a spark-producing metal alloy.

Quote: "This article is about the sedimentary rock. For other uses, see Flint (disambiguation)."

As observed in the above comments, many people think "lighter flint", is a spark-producing sedimentary rock. Therefore they will waste valuable time combing this article to end by cursing Wikipedia. "Lighter flint" needs to be added to the warning.
-- (talk) 23:18, 1 September 2011 (UTC)Doug Bashford

Flint Pebbles[edit]

Flint pebbles/silica pebbles were widely used to grind ceramic raw materials in ball mill. The main content is SiO2,the hardness is very good and the volume density is 2.66g/cm3. Flint pebbles/silica pebbles are produced through mining,sorting,processing,grinding and screening. Now more and more customers choose it to grind ceramic raw materials. — Preceding unsigned comment added by (talk) 08:11, 11 January 2013 (UTC)

Flint gravel used as aggregate[edit]

In the UK, at least, flint gravel is widely used as an aggregate in concrete and for road surfacing (bound in bitumen or resin). It is also used unbound for footpaths, driveways, courtyards, etc. Practically every country house in the south of England has flint gravel driveways. By 'flint gravel' I mean naturally formed small flint pebbles derived from flint nodules that have been eroded out of chalk. As this use of flint as an aggregate is probably its main economic use at the present time (since it is apparently no longer much used in glass and ceramics) I suggest it is worth a mention. I don't know about other countries, but I would guess that it is used in similar ways in the other 'chalk' districts of northern Europe. (talk) 14:45, 16 April 2013 (UTC)

Geographical distribution[edit]

Pity nothing on the worldwide distribution or occurrence of flint... Xenophonix (talk) 13:58, 4 July 2014 (UTC)

Variable quality[edit]

Flint occurs in different qualities- I have heard Grimes Graves flint described as "jet black, with excellent flint knapping qualities" and it was chosen and transported hundreds of miles for use at, for example Stonehenge, where other flints are much closer.

IceDragon64 (talk) 12:24, 16 September 2014 (UTC)