Is Krypton Rare?

Yes, krypton is rare. It makes up about 1.14 parts per million of air by volume, or roughly one krypton atom for every million molecules of air around it. That works out to 0.0001% of the atmosphere.

It isn’t the rarest gas on Earth, though. Xenon is scarcer, at about 0.087 parts per million, which makes it roughly 13 times rarer than krypton.

Radon is rarer than both. It’s radioactive and short-lived, so no one collects and bottles it the way the stable noble gases get handled. Among the noble gases in air, krypton is the fourth most abundant, behind argon, neon, and helium, and just ahead of xenon.

WestAir supplies krypton across California and Arizona.

Where Is Krypton Found on Earth?

Krypton is found in the atmosphere, spread thin and evenly through the air across the whole planet. Trace amounts show up in some minerals and meteorites too, but at levels far too low to work with. Air is the only practical source.

That sets krypton apart from helium, which is pulled from natural gas wells. Radioactive decay deep in the crust keeps generating helium, and gas-tight rock traps it underground in pockets rich enough to drill.

Krypton never collects like that. It stays diluted in the open air at the same faint level wherever you measure it, so there’s no concentrated deposit to mine.

How Is Krypton Obtained?

Krypton is obtained as a byproduct of cryogenic air separation, the same process that produces bulk oxygen and nitrogen. Air is chilled until it liquefies, then warmed slowly so its components boil off at different temperatures.

Krypton boils at -153°C (-244°F), well above nitrogen, oxygen, and argon. As the lighter gases evaporate away, krypton stays behind in the liquid and concentrates in the liquid oxygen at the bottom of the column, along with xenon.

That bottom liquid holds only a crude krypton-xenon mix, not pure krypton. It gets drawn off and distilled again to concentrate the two rare gases, which are then separated from each other and cleaned up to sellable purity.

Because krypton is so dilute, the numbers only work at scale. A plant has to move enormous volumes of air to gather a usable amount, which is why krypton comes from large air separation plants running mainly to supply oxygen and nitrogen.

How Does Krypton’s Rarity Drive Its High Price?

Krypton’s rarity drives its high price because so little of it exists to collect, and steady demand keeps buyers competing for the small amounts that reach the market. At those trace levels, a plant processes a staggering volume of air to recover a single cylinder’s worth.

Supply is capped further by krypton being a byproduct. A plant recovers it only while producing oxygen and nitrogen, so the amount available tracks demand for those two gases, not demand for krypton. When krypton orders climb, producers can’t simply make more.

That demand comes from established, ongoing uses: energy-efficient insulated windows, high-intensity lighting, certain lasers, and medical imaging.

The Bottom Line

Krypton is rare, useful, and priced accordingly, and none of that is likely to change soon. WestAir can walk you through your options and keep your supply dependable.

Lawrence Haynes

Lawrence is the Marketing Director at WestAir Gases & Equipment in San Diego, CA