Magnesium Carbonate: What is Rock Climbing Chalk Made Of?

So what is climbing chalk anyway and what is it made of? And what about liquid chalk? All questions answered in this incredibly awesome guide. 

Hey! By the way… this page contains affiliate links. So if you make a purchase after clicking one at no cost to you we may earn a small commission. Thanks for your support!

What Is Climbing Chalk?

Climbing chalk is a pivotal tool used by climbers to reduce the moisture in their hands and improve the friction between skin and rock, ultimately giving the climber a better grip and reducing the chance of falling off the wall because of sweaty hands.  

It is essentially the same as chalk used in other sporting areas such as weightlifting and gymnastics.

It comes in different forms: blocks, powder or as a liquid chalk, each with their own specific use which we will discuss below.

Magnesium Carbonate

Chalk is made from magnesium carbonate (MgCO3), a broken down form of the mineral Magnesite.  It is very effective at absorbing water without breaking down, therefore makes for a perfect companion for rock climbers with sweaty hands!

Mystery solved!

Well, almost.

Chalk is made primarily from magnesium carbonate, but the chalk you buy for rock climbing almost certainly has other things added to improve performance.  

In this article we’ll dive into the fascinating world of magnesium carbonate, discovering what climbing chalk is made of, as well as answers to all of the most asked questions.

We’ll find out about the different types of chalk, liquid vs powder chalk, how climbing chalk is made and for the environmentally conscious, is climbing chalk bad for the environment?

What is Climbing Chalk Made Of?

As well as magnesium carbonate companies often add other chemicals or minerals to make their chalk stand out from the competition.  Other ingredients often include drying agents, essential oils and limestone.  

Many of the more expensive chalks claim to use a purer form of MgCO3 that will fill the pores in your skin better and absorb water more effectively, but this may just be a finer version of the same mineral.  

There is, however, one ingredient that is more efficient at absorbing moisture than magnesium carbonate called Upsalite.

Upsalite

Mesoporous magnesium carbonate, patented as Upsalite in 2017, was only first discovered in July 2013.  

It is basically a new form of magnesium carbonate discovered by scientists to have the greatest surface area of any material on earth.  

This is exciting for science for a number of reasons, but also exciting for rock climbers too, as the larger the surface area of an element the better it’s ability to absorb moisture.  

Black Diamond introduced it to the market in 2018 as an ingredient in their chalk at the world’s largest sports exhibit ISPO and it proceeded to be awarded the best new and innovative climbing accessory of 2018.

Now Black Diamond offers it unrefined as “Pure Gold” or already premixed with their standard chalk as “Black Gold” with 10% Upsalite, claiming to have twice the moisture absorption of normal chalk.

Different Types of Climbing Chalk

There are different types of chalk, and which one you need depends on your specific needs.  For example, the top professional climbers are going to want to use the absolute best climbing chalk they can find, no matter the price.  

Intermediate or beginner recreational climbers will want something more affordable, and will probably not even notice the finer differences between elite climbing chalks.

Chalk can basically be broken down into three subcategories – block chalk, powder chalk (also known as loose chalk) and liquid chalk.   

Below we will explain in more detail each one.

Block Chalk

Climbing chalk is often sold in solid rectangular blocks.  This is the same as powdered climbing chalk, a magnesium carbonate (MgCO3), just in a solid form.  

There are certain benefits to buying climbing chalk in blocks.  The first is usually price.  

Because the chalk has not had to go through the final process to crush and filter it to a powder the savings are passed on to the consumer.  

Subsequently the consumer is required to break the chalk down themselves before using it (although some climbers, mainly boulderers, just rub the blocks over their hands before trying a climb).

Despite being a messy process, breaking pieces off from the block is a good way to regulate how much chalk you take with you on a climb, and is preferred over powdered chalk by many climbers for this fact.  

It also means you are less likely to lose half a bag of chalk trying to do that cool double knee bar or bat hang, or whilst on a super windy 40 meter pitch in Siurana.

Powder Chalk

This is what most people think of when they ask themselves what chalk is for climbing.  

It comes in varying degrees of consistency from a super fine chalk that’s as fine as dust, to a chunky mix of different “pebble” sized pieces and everything in between.  

The finer the chalk, the easier it will coat all the crevices in your hands and skin, but the downside is that it has a tendency to coat everything and produce great big clouds of dust.  

Great for atmospheric photos, but not so good for your wallet, your health or the environment.  

Combatting this is the chalk ball – a small refillable super fine mesh cloth bag that you carry in your chalk bag whilst climbing.  Just give it a squeeze and the chalk will filter through the bag onto your hands.

Liquid Chalk

Liquid chalk is simply a combination of regular climbing chalk and a type of alcohol, forming a liquid that you apply to your hands.  The alcohol evaporates leaving an even layer of chalk magically coating your hands.  

If you’ve just started climbing, liquid chalk has a number of benefits over its solid cousins.  One application can keep your hands drier for longer than regular chalk, great for long bouldering problems or as a base on sport climbs.  

If you have ever tried deep water soloing then you’ll know the problems of falling into water wearing a chalk bag.  Liquid climbing chalk solves this problem.  

If it seems quite expensive compared to regular chalk then why not check out our other article on how to make your own DIY climbing chalk using the link above.

Why Use Chalk for Climbing?

So you now know what climbing chalk is made from, you know the different types of climbing chalk, but you still might be asking yourself why use chalk for climbing in the first place?  

Well, we touched on this previously, but let’s look more closely.

Nowadays climbing chalk is inextricably linked with climbing.  One of the first purchases you make as a new climber is a chalk bag.

But this wasn’t always the case.  The gymnast turned climber, John Gill first started using chalk back in the 1950’s, realising that the properties gymnastics found desirable in chalk, or “mag” as they called it, could translate to climbing.  

Before this climbers would often just rub their hands on their trousers or in the dirt before trying a climb, leading some to believe this is where the term dirtbag came from – as when they picked up their bags afterwards they’d cover them in dirt!

Etymology aside, John Gill’s introduction of chalk into climbing, along with his prowess for dynamic movement and the development of bouldering has been seen as the “beginning of modern sport climbing in America.”  

This transition from traditional climbing more often associated with mountain climbing and alpinism to a more modern style has cemented the use (and necessity) of climbing chalk today, and it’s benefits are easily apparent.  

Just try a couple of routes without it and you will soon realise how quickly and how greasy your hands get, and how much more difficult it becomes to hold onto those tiny edges or soapy slopers.

How is Chalk Made?

Climbing chalk is made from magnesium carbonate by a process of extraction of magnesium from around the world.  

It has become quite a big industry and entire factories are dedicated to the production of chalk.  

This obviously has some detrimental impacts on the areas from which it is mined, so if you care about the world around you take the time to find out where your climbing chalk comes from and its environmental impact.

Finally,  we’re going to take a look at some of the most asked questions about climbing chalk.

Commonly Asked Questions

Is Chalk a Type of Rock?

Climbing chalk is made predominantly from the mineral magnesium carbonate.  Rock is an aggregate of one or minerals, sometimes this includes magnesium carbonate.  So, the short answer is no, climbing chalk is a mineral.  But once upon a time it may have been part of the structure of rock.

Is Climbing Chalk Bad for You?

Magnesium carbonate is also marketed as a mineral supplement, more commonly known as magnesite, to treat heartburn and upset stomachs by overproduction of acid in the stomach.  

So you could actually eat your climbing chalk as a mineral supplement, although we would never recommend this, especially as ingesting too much can act as a laxative – not good for you, and even worse for your belayer.

On a more serious note, any form of dust can act as a transmitter for bacteria – so the germs on your hands could easily be carried on clouds of chalk into the respiratory system of others through careless use.  

Some gyms have banned the use of powdered climbing chalk in the wake of Covid-19 because of this.

Is Climbing Chalk Bad for Your Lungs?

Any foreign body attracted into your lungs is not especially a great thing – this can most easily be seen by the high correlation of sufferers of lung cancer and smokers.  

Thankfully, though, most climbers are not addicted to huffing their powdered chalk, so the relatively infrequent amount you may breathe into your lungs will probably not do any long term damage.  

Furthermore, indoor environments such as climbing gyms often have good ventilation systems or air purification systems and high levels of cleanliness to reduce any harmful impact of the dust in the air.  

More worrying would be the journey to the gym if you live in a city with a high air pollution index.

Is Climbing Chalk Allowed on Airplanes?

Have you ever been through airport security with hundreds of grams of white powder in unmarked plastic bags and containers in your carry on?  This author has many times without even a second glance.  

Although you may worry about the chances of getting mistaken for some international drug dealer, in all likelihood this is not going to happen.  

Legally, most airlines we know of allow the climbing chalk on airplanes, but in case you’re of a nervous disposition or don’t want to have to explain yourself to a disgruntled worker then try to keep your climbing chalk in its original packaging in checked baggage.  

Liquid climbing chalk, however, does contain flammable properties, so it is always wise to check with the airline you’re flying with before departure and the company you buy your liquid chalk from.

Is Climbing Chalk Bad for the Environment?

To answer this it may be good to ask ourselves again what is climbing chalk made of?  Primarily constituting magnesium carbonate, a naturally occurring mineral, it seems unlikely that returning this to the environment is going to do much harm.  

Especially on harder rocks such as granite and quartzite, the chalk will have little effect.  

On softer rocks such as limestone or sandstone there is an argument that the buildup and repeated use of chalk can aid the polishing and deterioration of the cliffs.  

In fact some areas, most famously in the Czech Republic, chalk is actually prohibited as it is now in some areas in Colorado, Utah and Minnesota.  

The more detrimental effects of climbing chalk derive from the mass production techniques used to extract and process it. 

Unsightly scars are left in the environment from which it’s mined, not to mention the impact on local wildlife and the pollution from the factories and transport needed to get the finished product into our chalk bags and onto our hands.  

Luckily most climbers are very conscious of their impact on the environment and with a bit of searching can find companies offering climbing chalk from sustainable sources.

Does Climbing Chalk Go Bad?

Simply put, no.  If you’ve managed to make your climbing chalk go bad then you either have magical powers or have left it out in the rain.  

Perhaps in a super humid environment exposed to the air for many months it may possibly go a bit funny, but after living and climbing in south east asia for a number of years this author’s experience would indicate not.

Is climbing Chalk Flammable?

Powdered or block climbing chalk is not flammable, however the alcohol in liquid chalk is.  

Personally, we have never had any success in getting it to light ourselves, but as we mentioned above, if you’re planning on taking a flight maybe check with the airlines rules first.

Further Reading

So now you know almost everything there is to know about magnesium carbonate, take a deep breath, focus on the next move, chalk up and go strong!  If you’re craving more information then check out two more of our informative articles related to chalk below. (what is chalk made of, climbing)