I have a race of people who have silver blood. Thing is, I'm really trying to keep it as realistic as possible despite this being a fantasy world. The blood has raw magic energy in it as well, but doesn't mix so were you to collect blood, there would be a silver/bright red (the color of raw magic here).

So far, and this is all working and will change with more information. Some things I know so far that may or may not be affected by the compound/color upon oxidation choice: when they blush they do get pink-red tinge because of the raw energy. If one of these people, for some reason doesn't have the energy in the blood, they pale instead. I have never specified if the blood changes color when they bleed or between artery/vein blood, but perhaps upon hitting open air it might turn black. Bruises are a ruddy gray to a charcoal black.

My only caveat is that they have to remain looking enough like "humans'-- the skin color is a narrow range of different levels of caucasian (ranging from kind of pale to kind of olive-y tan depending on activity level. They usually remain very light). They are also of a different blood than other races there as they are a sort of "invasive" species in that they were created long after the other races were a thing. Those with raw energy in the blood will be "pinker" than those who do not-- If there is none, they will be very, VERY pale.

Any help would be so appreciated. I've tried looking for ages, to no avail! I want to make this work! My best guess right -now- is that perhaps the blood is colorless, and it's the -plasma- that's silver?

  • 6
    $\begingroup$ Do you want the creatures' blood to actually be silver, or do you simply want it to be silver colored? The latter is probably much easier to accomplish than the former. $\endgroup$
    – user
    Commented Dec 21, 2015 at 8:16
  • 3
    $\begingroup$ Do not overthink it. First... saying "Ok, I have magic, but I want realistic magic!" is just to work against yourself. Magic is called magic precisely because it is not realistic. And What you want is not realism, you want credibility. Realism is usually a good way to make something credible, but not always. On the contrary, if you try too hard to make magic seem realistic, then you are hurting the reader's Suspension of Disbelief. Remember the Midi-chlorian debacle? That is how you kill magic. $\endgroup$
    – MichaelK
    Commented Sep 27, 2017 at 15:54

5 Answers 5


Depends on what you really mean by silver. Silver, the element, (Ag) can be bright and shiny like chrome. Silver oxidizes, like iron does. However, iron turns red when it oxidizes. That's why our blood is red. Silver turns black when it oxidixes.

If you want to use actual silver, and have your race breathe oxygen, then the blood isn't going to appear silver in color.

Also silver is solid at room temperature. Mercury (also known as quicksilver) is liquid at room temperature and very shiny. Problem is, when it oxidizes it turns orange, red, or yellow depending on how fine the crystals are.

The color white and the color silver have historically meant the same thing if that helps.

If you can be flexible with your definition of the appearance of silver there is titanium oxide. It can be white or dull grey in color. In my mind, this is your best bet.

Of course, nothing says your race needs to breathe oxygen. But carrying oxygen is the primary function of the only kind of blood I know. Your race could be doing something different with it.

  • 4
    $\begingroup$ Blood of most insects does not transport oxygen (insects use tracheae for it), but only nutritional substances. $\endgroup$
    – BartekChom
    Commented Dec 21, 2015 at 6:27
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    $\begingroup$ @BartekChom and that is why insects are so small. $\endgroup$
    – Kreiri
    Commented Dec 21, 2015 at 8:22
  • $\begingroup$ Of course, besides transporting oxygen, our blood also transports nutritional substances, and that's just as important. Moreover it also transports information in the form of hormones. And it transports repair material for wounds (thrombocytes). And finally, it also hosts large parts of our immune system. In short, the blood is our main transport system, for all sorts of stuff. $\endgroup$
    – celtschk
    Commented Dec 21, 2015 at 11:17
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    $\begingroup$ Arguably the most important role of blood is to transport carbon dioxide. $\endgroup$
    – SFWriter
    Commented Sep 27, 2017 at 22:13

Having blood that is literally a metallic silver color while also transporting nutrients and oxygen is going to be difficult, if not impossible. The accepted answer to this question provides a list of different oxygen-carrying proteins and their colors when oxygenated and deoxygenated. The closest are probably hemocyanin, which is colorless in the veins, and coboglobin, which is colorless in the arteries. Other proteins not listed here might give a grayish or milky-white color; but I don't think there's any for an aqueous solution to give you a metallic sheen.

However, who's to say it has to be an aqueous solution? You're already talking about raw magic energy here, so these creatures' blood could literally be liquid mercury and it wouldn't make any less sense from a scientific perspective. Or liquid gallium, if you're worried about them poisoning anyone they bleed on, although their home environment would have to be a bit warmer than Earth for that to be feasible. Gallium melts at 29.76 °C, between room temperature and human body temperature.

Alternatively, their blood might be a normal color when in their circulatory system, but turn silver upon exposure to air. Much as exposure to air triggers human platelets to release sticky proteins and start coagulating, it might trigger your creatures' blood to produce a film of some material that looks like silver foil. I'm not sure what that material would be or how it would work, although a strange type of atmosphere* could do it. Or it could just be magic.

*If your story happens to take place on a world with an atmosphere rich in hydrogen (such as this one, or any old gas giant), it could be silver ions in the blood being reduced by the hydrogen in the atmosphere and precipitating out as silver metal. However, a creature from such a planet would have great difficulty surviving for very long on Earth without a space suit.

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    $\begingroup$ 'We have to get through this aluminium door!!' 'sigh Fine. Give me a knife' $\endgroup$
    – Joe Bloggs
    Commented Sep 28, 2017 at 14:29

Rather than focusing on having the blood be possessing of metals, perhaps the cells comprising the majority of the blood contain a refractive meta-material whose structure reflects light in such a manner that it looks silvery. Such things are actually quite common in nature and are responsible for iridescence among other phenomena.

As for why they would possess such a feature? Maybe the unusual structure of their blood cells are what enable them to "drag" the magical fluid around the body...


Perhaps the blood contains very fine particles or colloidal silver. These could be encapsulated in some form of membrane which would prevent oxidation and would help ease the transportation of them in the blood stream. These metallic particles might be needed for reinforcement of the skeletal structure to provide extra strength. Haemoglobin could also be present giving the blood its red component colour as well as providing oxygen and removing carbon dioxide.

Damage to tissue might well rupture some of the particle membranes causing oxidation. This could be one of the bodies defence mechanisms. Once some silver started oxidizing it could create an inflammatory response rupturing further particle membranes until any wound had scabbed over with high Silver oxide content.

Damage to tissue without breaking the skin might cause different oxidative processes such as the formation of Silver Phosphate which is yellow or other organosilver compounds might form to give almost any colour depending on the exact chemical composition.

Silver might also be used in the body as a catalyst either in its elemental form or more likely incorporated into Silver containing enzymes. It also has some antibiotic properties.

Silver would have to be reasonably abundant in the environment to make this credible.

An alternative would be for the blood to contain a colloid suspension of particles of a size suitable to create diffraction effects producing a range of colours for example:


gold particle but a wide range of materials can form colloidal suspensions.


I think it could actually just be silver

Human hemoglobin is composed of iron which acts as an oxygen carrier. This is why when blood is oxidized it turns red (rust).

Silver is also a metal which easily oxidizes. I believe it could be used in replacement of iron in the blood. Because it has a smaller ionic charge than iron you would need more. Depending on the quantity their blood could actually look shiny silver when unoxidized and tarnish when oxidized.

Would be interesting having people hunt them for their blood.

Nickel could also be used:

Just as iron and silver it can be oxidized. When unoxidized it appears shiny kind of like silver when oxidized it just dulls slightly.

  • 1
    $\begingroup$ I don't see how this is any different than a shortened version of CandiedOrange. $\endgroup$
    – Vylix
    Commented Sep 27, 2017 at 17:10
  • $\begingroup$ Everytime I read his answer I don't see the same detail on how hemoglobin works. Plus I suggested nickel which he didn't. $\endgroup$
    – anon
    Commented Sep 27, 2017 at 17:18
  • $\begingroup$ errrm, hemoglobin is composed of protein and coordinates iron in a heme group. Iron is a very minor component of hemoglobin. Some details could be tightened up but I like your answer anyway. $\endgroup$
    – SFWriter
    Commented Sep 27, 2017 at 22:16
  • $\begingroup$ Our blood is always red. De-oxygenated blood is slightly darker, but still red. Some veins appear blue because of color scattering; same principle that causes us to sometimes have blue or green eyes but never hair or skin - the pigment or lack thereof in certain structures causes the color of light to sort of reverse. $\endgroup$ Commented Sep 6, 2019 at 12:01

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