# Obsidian vs Steel Tools



## Jabrosky

In one of my prehistoric fantasy stories, I have a trio of hunter-gatherer ladies who hunt with obsidian-tipped spears. One of these characters gets her spear destroyed by a T. Rex and needs a replacement, but obsidian is hard to find in their jungle homeland except in volcanic foothills. The heroines decide instead that they should visit a village of horticulturalists who forge their weapons out of steel. The meat of the story should have something to do with the cultural contrast between these hunter-gatherers and the settled horticultural people.

Would steel really be a preferable material for spear-points over obsidian? I know metal is preferred over stone in most instances, but obsidian is special in that it's a very sharp material that is favored for surgical scalpels. That's why my heroines are using it to hunt dinosaurs in the first place. Does steel have any advantages over obsidian that would make it a worthwhile replacement?


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## wordwalker

Other people can answer this in more detail, but:

Obsidian is better-- once. It really can be about the sharpest edge we've ever discovered, because it's very much on the "harder, sharper, more brittle" side of the breaking-vs-blunting continuum that steel balances so well between. So if you stab someone with an obsidian spear you'll slice right through everything except the bone and any armor (or wooden shields), and then the obsidian will blunt and quite possibly break. After all, it's _glass_.

(But if you're hunting dinosaurs, maybe one-shot weapons are exactly what you want!)

By the way, are you sure the village offers them steel as an alternative, in a prehistorical fantasy? Not iron, not bronze, not stone?


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## CupofJoe

From what I know Wordwalker has it about right.
Steel and Iron are reusuable and can be honed to an edge relatively easily where as [apparently] knapping obsidian and flint is a skill that can take a long time to learn and if you get it wrong you have to start again.
One other drawback of Obsidian was length of blade. I think that a cutting edge of more than 2-3 inches would be difficult to make, at least repeatable. I'm sure I've seen Mayan or Aztec weapons that had shortish obsidian "teeth" along a wooden "blade" to make a 2ft sword.


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## Chilari

Obsidian is brittle. The way the blades are made is a clue to this - strike it sharply with a rock and a shard will come off. Do that in a controlled manner and you'll make a blade. In an uncontrolled manner, like say a fight, and it could easily break it. Obsidian thus makes for a great cutting blade, for surgery or butchery, but keep it away from impacts. In that respect it most resembles the Japanese katana, which were made from inferior iron and needed to be folded, but would shatter on impact and thus had to be used to slice rather than chop, or they would break.

For a spear point, therefore, which is an impact weapon, steel would be preferable. You'd be able to have a larger spear head, and you'd get hundreds of uses out of it. You also need less time to make a replacement.


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## Jabrosky

wordwalker said:


> By the way, are you sure the village offers them steel as an alternative, in a prehistorical fantasy? Not iron, not bronze, not stone?


Steel is basically iron with carbon added. I don't know if you need industrial-era tech for that.


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## Noma Galway

Wordwalker said:
			
		

> So if you stab someone with an obsidian spear you'll slice right through everything except the bone and any armor (or wooden shields), and then the obsidian will blunt and quite possibly break. After all, it's glass.
> 
> (But if you're hunting dinosaurs, maybe one-shot weapons are exactly what you want!)


If you won't cut through armor and bone, would obsidian really work on dinosaurs?


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## Chilari

But to make steel you do need to get firing temperatures up higher than iron. And iron needs higher temperatures than copper. That's the problem: the iron age was slow in coming precisely because of the difficulty in smelting it, and once it had arrived bronze was still a commonly used metal because it was easier to work. You could menipulate iron at grey cast level (not actually melting it properly, but making it maleable to make things with) several hundred degrees cooler than is required to melt it for making steel. And copper is cooler still. The lower temperatures for copper or grey cast iron could be achievede with a relatively simple kiln setup, but steel requires better insulated furnace technology. It also requires that people have the idea of adding carbon and learn the skills necessary to make it work.

The amount of time between the stone age and the steel age is phenomenal. Even going from the neolithic, when the finest stone tools were made, to, say, the Roman period is several millennia. Meanwhile, the whole neolithic revolution introduced agriculture - you say your heroines visit a horticultural village, well, that's perfectly acceptable in the stone age. But for them to have advanced metalworking, in a settlement which should be subsistence level for food production (otherwise it would have grown larger - food surplus leads to population growth which leads to greater efficiency in food production which leads to individuals having dedicated jobs in non-food production roles, like as potters, weavers, smiths etc).

Basically what I'm saying here is that a village is unlikely to be sufficiently large to support a steel worker and the necessary supporting trades (it requires a lot of fuel, so charcoal burners and brickmakers at the least) and almost certainly wouldn't be advanced enough, if there are still people in contacted cultures using obsidian for non-ceremonial use, to have developed the necessary predecessor metal working technologies (copper age developed into the bronze age with the addition of tin and other minerals to strengthen copper into bronze; iron working proved to be a different kettle of fish entirely because it has different propoerties such as the ability to mend and sharpen tools without the need to melt them down and remake them).

It's not about needing industrial era technology for steel - as I say, the Romans had steel, and once the iron age began steel was relatively quick to follow, in terms of centuries rather than millennia as was the case with the stone, copper and bronze ages. But it does require greater technology and simply people thinking of taking the innovative step from iron to steel to develop. It requires sufficient technology to heat the metal to 1425C where copper only required 1084C to melt and alloy with tin (which melts at far lower temperatures) and then make into tools and weapons. And that heating technology is tricky stuff. I mean, a standard largish bonfire in your garden can almost get hot enough to melt copper. Add a little clay insulation to make a rudimentary kiln and keep a good flow of oxygen and you're golden. But adding another 400C to that is hard. The technology required to make the kind of insultation you need, the skills and the manpower and the time and the fuel requires is far beyond the requirements to make bronze stuff. That's why the bronze age lasted thousands of years - because it took that long to (a) consider that another metal might be more useful, (b) work out how it could be manipulated and (c) develop the technology to reliably generate the temperatures required to work iron.


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## Jabrosky

It sounds like I should go with iron or copper as my metal alternative then.

That said, I still think obsidian might have utility against dinosaurs (except maybe the really huge ones like the sauropods). Early Native Americans were apparently able to use obsidian-pointed spears against fairly large game such as mammoths.


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## wordwalker

Agreed, obsidian might be good against dinosaurs. 

At least, against a big carnosaur that gets too close to your land-- and you break out the best weapons and tactics to set up a few perfect stabs at it before it starts ripping your heads off. But it takes _how_ long to chip one of those spears, CupOfJoe? Plus, how much of it can they come across? The harder the obsidian heads are to replace, the more they'd conserve them by sticking to flint for basic hunting.

Besides, it's believed the classic caveman weapon for hunting mammoths wasn't spears at all. It was torches, combined with a spiked pit or just a cliff. Never risk skewering something that big if you can chase it to where its own weight would do the job.

Edit: I don't think they'd hunt the larger sauropods at all. Even if you could kill one, almost all the meat would rot before they could eat it. I doubt smokehouses or salting would be feasible, not on THAT scale.


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## Penpilot

One point to add to the great points above. Obsidian is volcanic glass, so maybe think of it like glass in terms of it's pros and cons vs a metal.


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## CupofJoe

Most of my knowledge come from watching people knap flint in to a arrowheads and chatting to them as they did it.


wordwalker said:


> But it takes _how_ long to chip one of those spears, CupOfJoe?.


It took a couple of hours for a knapper to break a nodule to a rough [but serviceable] arrow head. Someone did mention spear heads and the knapper said that the bigger the blade the much long it took, twice the size at least four times as long [there are two edges]. He was very clear that any knap could ruin a tool [he always called then tools and not weapons] and then you'd have to start again or change what you could make. He was also very clear that you had to go with the stone as you knapped and make what you could get, scrappers and arrowhead would be easier than knives or spearheads. You couldn't say _I will make a knife today_, you had that hope and aim but you had to go with the stone.


wordwalker said:


> .Plus, how much of it can they come across?


 That might be the big problem. Good flint nodules are difficult to obtain and harder to carry [stone is really heavy]. I've read that there are mounds of broken flints where humans found a good seam and broke open thousands of likely rocks to find they ones they wanted. It seems that most of them were roughly hewn on-site and then taken away to be finished. I got the feeling that it would be a camp or winter job, to make tools for the year ahead. If they did make tools by firelight without protective glasses, then I can't help wondering how many half blind ancient people there were... 
I know that good flints were traded all over Europe.
I've just seen some knapping course are running local to this spring... I might give myself a new year's present.


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