How could you explain black firebreath?

I'm currently writing a medieval fantasy novel where one of my main characters is a human who can shift into a dragon that breathes a black colored fire. I would only call it black fire for the sake of simplicity, as it isn't a literal black colored fire, and it should be explained as an added pigment that makes it appear dark.

I would also like to know if say, this dragon blew fire upon different substances (like different metals, earth, wood, etc...) would this pigments color be affected drastically? Also, if this pigment is obtained by diet, or some biological chemical reaction, or an external environmental factor. In addition to this, how would this dragon and other dragons be resistant to this pigment (in the sense that they would not be wounded, or inhaling a sort of poison), as well as other animals/plants in the environment around them. I would much prefer to give an actual explanation, instead of giving a vague answer of 'it's just magic'.

Diana

Posted 2017-09-04T12:07:06.300

Reputation: 31

Please define "fire". This might sound stupid, but if you just mean "a very hot gas", this would be way easier. If you go with a standard definition, this is impossible (just like you can't have dry water). One could add pigments of some kind to that flame that makes it appear very dark but the fire itself wouldn't be. Have you considered that our brain just interprets complex mixtures of light as colors? Another species in another world might perceive white as black for example. – Raditz_35 – 2017-09-04T12:10:58.210

Welcome to WorldBuilding Diana! We have some pretty interesting questions on the site about dragons already, such as How could dragons be explained without magic?. Are you primarily interested in what substances would produce a completely black flame or in the realistic dragon design? It would be nice if you could [edit] your question to clarify that a bit. If you have a moment please take the [tour] and visit the [help] to learn more about the site. Have fun!

– Sec SE - clear Monica's name – 2017-09-04T12:12:17.237

For the question on a human shifting into a dragon, we do have a whole tag for shapeshifters, and another for dragons. You may want to look through the questions thus tagged. We even have one question tagged with both of those, although it doesn't look relevant to your scenario.

– a CVn – 2017-09-04T12:15:46.703

You can't easily make a black flame as explained https://worldbuilding.stackexchange.com/a/82443/17720

– Bellerophon – 2017-09-04T12:15:53.907

1@Secespitus I read this as the question being about black fire, and the part about the human/dragon shapeshifter is more of backstory to the question at hand. Diana, if this is wrong, then please [edit] to clarify exactly what you are looking to know. Sometimes this can be as simple as **boldfacing** the specific question. – a CVn – 2017-09-04T12:18:17.310

Your new edits make this a curious case. From "this is impossible" you just went to "basically anything would do this". Creating black smoke is extremely easy. I'm sorry if I mislead you, I did not anticipate this. Since you are writing an actual novel, I don't think it is too much to ask if you could do a quick research on what would do that so we can tell you about the biology? The problem now is that there are basically infinite answers and you are asking for a) a pigment b) how to create that pigment c) something about earth. If you could eliminate a), b and c become viable questions – Raditz_35 – 2017-09-04T12:48:53.647

@Raditz_35 Perhaps an element like carbon, and it's incomplete combustion. Or maybe the thermal decomposition of a certain compound that produces a dark colored vapor/smoke. – Diana – 2017-09-04T13:30:01.647

Answers

The answer could be as simple as very hot smoke. This could constitute a form of "blackfire". This is usually produced when something with a lot of carbon in its make-up burns and the combustion is incomplete. Alternatively , this could be very hot oil in an extensive spray of fine droplets. Either will be mostly black, dense and hot. If the temperature of the smoke or oil spray is higher enough it could burn away invisibly, but initially there will be an exhalation of burning hot blackness.

This provides an explanation of what could be blackfire based on plausible scientific assumptions. However, it may be necessary to use magic to produce copious amounts of hot dark smoke or a hot oil droplet spray needed to make the blackfire. Dragons are like that, you need a certain amount of magic to make them work.

a4android

Posted 2017-09-04T12:07:06.300

Reputation: 36 258

2If you look at an oil well fire, the flames at one point turn to black smoke. The difference at that point is that the emissions from the fire are not hot enough to glow: flames are hot incandescent gas and that stuff has cooled enough that it is not incandescent. That black stuff is still very hot (if not red hot) and would still burn the bejeezus out of anything it touches. If your dragon blew very hot black carbon it might not glow but once the oxygen got to it and it burned, it would glow just fine. – Willk – 2017-09-04T23:04:52.720

@Will Just the sort of special effects I was hoping for. A blast of blackness turning into blazing incandescence. – a4android – 2017-09-05T12:59:58.310

Black flames, no, you can get some odd colours though, many Strontium salts burn with an oddly dark and uniform red flame and Potassium burns with a purple flame that can be close to what we call "black" in roses depending on the impurities in the metal, so can Iodine. so something dark purple/red could be done.

If by "Fire" you mean a hot oxidising blast might I suggest looking at the Plutonium Dragon, yes I know it's deliberately stupid and over the top but it could have something like X-Ray or Gamma as a breath weapon which you wouldn't see at all except where it charred the target.

Ash

Posted 2017-09-04T12:07:06.300

Reputation: 36 902