Are Diamonds Flammable? Will They Burn In A Fire?


As an Amazon Associate, I earn from qualifying purchases (at no added cost to you).

They say that diamonds are a girl’s best friend and that you should pay 3 month’s salary for a diamond engagement ring (“they”, of course, are the diamond marketing people). And the diamond has been a highly sought-after statement of fashion and, occasionally, love for a long period of time, but is that engagement ring a fire risk, and should you, perhaps, choose another stone rather than a diamond?

Diamonds are not flammable. They will not readily catch fire and need extremely high temperatures in order to burn. Diamonds can burn around 1562 degrees Fahrenheit (850 Celsius) and melt at 7280 degrees Fahrenheit (4026 Celsius).

These are extreme temperatures that you don’t see eveyday. However, there are some scenarios that could cause your diamonds to be exposed to heat like this. Let’s take a look.

Also read: What Makes Something Flammable?

What Exactly Is A Diamond?

are diamonds flammable?

Diamonds are a fascinating gemstone. That’s because they’re made of nothing but carbon.

Yes, the same carbon that coal or graphite are made out of. Graphite is the most chemically stable form of carbon, but even though this is an absolute truth – a diamond won’t turn into graphite even if you leave it for the longest of times. 

Diamond has the unusual property of being both the hardest, naturally occurring material known to man as well as having the highest thermal conductivity of any natural material too. 

So, as well as being used for pretty jewelry, diamonds are also used in industry for cutting and polishing other substances. 

They also retain an extraordinary level of chemical purity (it’s very hard to contaminate a diamond with other substances) and they have a very interesting level of optical dispersion (the ability to split and disperse light into many colors). 

Also read: Is Playdough Flammable?

Why Are They So Popular and Valuable?

We’d love to be romantic and tell you that it’s because of the scarcity and rarity of diamonds but then, we’d by lying to you. 

While there is a limited supply of diamonds, it’s not so limited that it would justify the incredible prices charged for jewelry containing the stone.

That’s due to two things.

  1. The De Beers company’s absolute monopoly on the diamond market and thus, the artificial restraint on supply of diamonds to the market
  2. The De Beers company’s incredible marketing campaigns. 

Diamonds aren’t worthless but without the above, they’d be worth a whole lot less and, probably, be a lot less desirable too. 

Can They Catch Fire?

Under ordinary circumstances, you don’t need to worry about a diamond catching fire. In fact, thanks to their thermal conductivity – it’s very hard to set a diamond on fire.

However, it can be done – you just need some specialist tools, and please, whatever you do, don’t try this at home – that is liquid oxygen and a super-heated torch. 

After all, carbon is flammable and diamonds are nothing but carbon.

Take a look at this setup:

This supplies a lot of heat and rather more oxygen to the surface of the diamond than it would encounter in the air. 

What Happens If You Burn A Diamond?

Diamond is pure carbon (or very nearly). That means when it burns there are only two possible products – carbon monoxide and carbon dioxide.

If the diamond doesn’t burn completely – you may get a slightly sooty flame as carbon molecules are extruded into the escaping gases. 

If it burns fully, both carbon dioxide and carbon monoxide are colorless and odorless. You’d just see your diamond disappear. 

Do They Burn Or Melt?

A diamond can melt and, indeed, if you can heat it up to about 7,280 degrees Fahrenheit (a temperature far hotter than that which occurs in a typical domestic or industrial fire) then it would melt.

Take a look at this attempt to melt a diamond using liquid oxygen:

But, as it began to melt something else would happen to the diamond. It would begin to turn into graphite.

In fact, over millions of years without getting hot, a diamond will very slowly turn into graphite. In billions of years a diamond would eventually be just a pure lump of graphite but if you add heat – it will speed up that conversion process. 

However, this would have to be done without the presence of oxygen because diamond burns (ignites) at around 1562 degrees Fahrenheit in the presence of oxygen. 

Can Heat Damage A Diamond?

Can heat damage a diamond? It would depend on how you define “damage”.

Heat can, as we’ve seen, turn a diamond into graphite but, technically, that was going to happen anyway – so, it might not be “damage” from everyone’s point of view.

However, if a diamond burns then yes, it will be damaged because there will be less diamond available to you at the end of the process than at the beginning. 

This is going to be a fairly atypical circumstance though and we don’t think you’re going to find any problems insuring a diamond against fire damage – it’s not a huge risk. 

Take a look at what happens when a diamond is burned:

Can They Burn In A House Fire?

In theory, yes, a diamond could burn in a house fire. A house fire can get up to 2,000 degrees Fahrenheit and that’s more than hot enough to help a diamond burn.

The big question as to whether it will burn, or not, is how much oxygen is available?

As we’ve noted the easiest way to get a diamond to burn is with liquid oxygen and that’s because it greatly increases the amount of oxygen available to fuel the fire. 

But even in a standard house fire, diamonds can burn and decrease in size and clarity. 

Related Articles

Is Glass Flammable?

What Is The Temperature Of Fire? How Hot Does it Get?

House Fire Temperature: How Hot Does It Get?

Chase

I have been a Firefighter in Northern California since 2012 and a Paramedic since 2008. My site is dedicated to helping answer questions people have about the fire service. I am passionate about helping to share what I have learned and assisting those who are pursuing a career as a firefighter. Thanks for coming to my site!

Recent Posts