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What turns fire purple?

Fire is typically seen as red, orange, or yellow in color. However, under certain conditions, fire can appear to be purple. So what causes this unusual purple flame? There are a few key factors that contribute to fire turning this vibrant shade.

The Science Behind Purple Fire

For fire to burn, a fuel source, oxygen, and heat must be present. The most common fuels – wood, paper, or natural gas – burn orange or red because of the soot they produce. This soot is full of carbon molecules that glow orange when heated. However, if a fire is hot enough, these carbon molecules can run out of oxygen. This causes them to stop glowing orange and allows other colors to show through.

Certain metal salts produce a purple color when heated in a flame. These metals include potassium, rubidium, cesium, and indium. When these substances are added to a fire, the metals get hot enough to emit energy at wavelengths corresponding to purple light. This overrides the orange glow from carbon molecules and turns the flames purple.

Potassium is a common contributor to purple fire. When potassium chloride is added to a flame, the potassium ions become excited and emit a purple glow. Fireworks commonly use potassium to produce purple sparks and flames. Rubidium and cesium produce an even deeper violet color thanks to their lower emission wavelengths. Indium chloride is also used to get bright blue and purple fireworks.

How to Turn Fire Purple

To turn a standard fire purple at home, potassium is the easiest option. Chemical fertilizers and products like potassium chloride or potassium nitrate contain plenty of potassium to do the trick. Simply toss a small amount of one of these potassium-rich compounds into an existing fire. The potassium will begin glowing purple as it burns. However, take caution – too much potassium can cause the fire to burn more violently.

For brighter and longer-lasting purple flames, look for specialty fire colorants online. These chemical mixtures use potassium, rubidium, cesium, or indium to provide vibrant purple hues. A little bit of these colorants goes a long way, creating striking purple flames. Be sure to check the safety instructions and only add small amounts at a time.

Purple fire can also be achieved with certain pyrotechnics. Fireworks use potassium and indium compounds to produce stunning purple bursts in the sky. These vivid purple fireworks can be found at major holidays like New Year’s Eve or the Fourth of July. Indoors, potassium-infused sparklers and fountains glow a brilliant violet color as they burn.

Why Purple Fire is Rare

Even though purple fire is possible, it remains relatively rare in nature. The main reason is that most natural fuels don’t contain the specific metal salts needed to produce purple flames. Wood, gasoline, natural gas, and other common fire fuels burn orange and red due to their high carbon content.

Potassium, rubidium, cesium, and indium are relatively uncommon in nature. Potassium is the most abundant of these elements, but it usually isn’t present in high enough concentrations to yield purple flames. Exceptions occasionally occur after meteor strikes or rock quarry explosions expel potassium-rich dust into the air. But in general, these metals aren’t available to burn in most natural settings.

The high temperatures and specialty chemical combinations needed to generate purple fire mean it requires man-made conditions. Fireworks and other pyrotechnics use very specific formulations to achieve vivid purple colors. Until these metals are deliberately added, fire will continue burning orange and red in most environments on Earth.

The Significance of Purple Fire

The rarity and difficulty of creating purple fire lends it an air of mystery and intrigue. Throughout history, purple dyes and pigments have been associated with royalty, nobility, and high status. The vibrancy and uniqueness of the color purple continues to be prized today. So witnessing purple fire can be a particularly spellbinding experience.

Purple fire has often signified paranormal or spiritual events. Unexplained purple flames are said to herald the supernatural, from magical rituals to the underworld itself. The rare sight has an otherworldly quality that feels transcendent. This enigmatic energy has made purple fire an emblem of magic, the occult, and fantasy stories to this day.

Science has uncovered how this anomalous blaze is possible. But the symbolism of purple fire still burns brightly in our imagination. Its rarity and mysticism will likely continue to captivate those fortunate enough to witness its entrancing glow.

Potential Dangers

While beautiful, it’s important to keep safety in mind when working with purple fire. The potassium and metal salts used to produce these flames can be hazardous if handled improperly:

  • Use caution when adding potassium, rubidium, cesium or indium compounds to an open flame. Adding too much at once can cause flames to rapidly intensify.
  • Be aware that potassium chloride is a skin and eye irritant. Wear protective gloves and goggles when using it as a flame colorant.
  • Potassium nitrate and other oxidizers enable fire and can be explosive. Keep these compounds away from open flames until ready to use.
  • Specialty flame colorants will often come with a full set of safety instructions. Carefully follow all provided precautions.
  • Metal salts used in fireworks and pyrotechnics are strictly regulated. Do not attempt to make your own without proper training.
  • Attending a professional fireworks display is the safest way to enjoy purple flames. Avoid lighting amateur fireworks on your own.

With prudent safety measures, purple fire can be an amazing sight to behold. But always put safety first to avoid potential hazards from unstable or improperly handled chemicals.

Notable Examples

Purple fire may be uncommon, but this unique phenomenon has made appearances both man-made and natural:

  • Potassium-laced Meteors – Meteor strikes where potassium is an element sometimes produce transient purple flames.
  • Purple Fireworks – Pyrotechnic compounds with potassium, rubidium, or cesium create vivid purple colors.
  • Borax Flames – Heating borax can yield an intense purple-blue flame.
  • Cobalt Glass – When heated, cobalt turns molten glass a saturated purple color.
  • Magic Tricks – Magicians use potassium, rubidium, and other chemicals to conjure purple fire.
  • The Joker – The DC Comics villain is known for his purple suit and use of purple pyro in his crimes.
  • Spiritual Ceremonies – Purple fire is said to be part of certain occult rituals and mystical practices.

Rare natural events and deliberate man-made efforts have produced purple fire over the centuries. While this phenomenon is not fully understood, its vibrant glow never fails to fascinate.


Purple fire defies expectations by burning in a color seldom seen among flames. But under the right conditions, certain elements can produce an enchanting violet blaze. Potassium, rubidium, cesium, and indium are key ingredients that override the usual orange glow of fire. Though difficult to generate, purple fire can result from natural mineral deposits or pyrotechnic compositions.

This unique fire has inspired intrigue throughout history. The rarity and mystery around purple flames have made them a symbol of magic, spirituality, and the supernatural. However, modern science has uncovered the secrets behind this alluring occurrence. With careful chemical handling, purple fire can be created safely and responsibly.

So while not fully understood, purple fire continues to kindle human creativity and imagination. Its gorgeous glow and symbolic power ensure purple flames will captivate us for centuries to come.

Metal Wavelength Flame Color
Potassium 404 nm, 766 nm Violet
Rubidium 420 nm Violet-blue
Cesium 459 nm Blue
Indium 451 nm Indigo

This table shows the different metal elements that can produce purple fire and the emission wavelengths that lead to violet, blue, and indigo colored flames.