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5 Steps to Find, Identify, and Prepare Natural Flint to Make Fire

Finding flint in the wild can be a difficult task, especially if you don’t know where to look or exactly what to look for. I have often searched for flint and have found the entire endeavor to be somewhat frustrating. So, I did some practicing, and this is what I learned.

Natural flint is easiest to find along river or creekbeds and will often appear glass-like with a waxy appearance. While commonly gray or black, color is the least reliable way to identify flint. Unlike most other rocks, flintstones will scratch glass and make a spark when struck against steel.

Let’s face it, there’s nothing more satisfying, in a primal sense, than creating fire with nothing but some rocks and sticks. Finding and working with flint is one of those skills that has been lost to time in Western culture. However, it’s actually easy to identify and prep for use once you get the hang of it.

Step #1: Learn where to Find Flint

Scope and Map

If you want to find flintstones more easily, you should consider two main things:

  1. The history of the area you intend to search.
  2. The properties of the flint type found in that specific area.

Flint occurs in large deposits in some areas. In these areas, you find it easily on the ground, under huge sedimentary rocks, on Jurassic & Cretaceous beds, or slightly covered in gravel.

In areas with fewer deposits, flint can be found alongside water bodies like riverbanks, creeks, and beaches or slightly beneath limey debris.

The characteristics and properties of flint vary depending on the locale, so it is important to understand your location before you start searching.

Using the History of the Area to Help Find Flint

Understanding the history of your location can help you identify flint. It allows you to know where and how to find deposits, so you don’t waste time searching the wrong places.

Map-Out the Area and Search

Depending on the information you gather about the area’s history, you can start searching for flint around the most promising areas. Here are a few ideas of where to look:

  • Check rock deposits – If the area has huge rock deposits, (like Ozark, Missouri) you are likely to find flint lying on the ground among the gravel. Also, sometimes flint will be hauled in with gravel by construction crews and laid down to build roads and other projects. There is one such road behind my house.
  • Look in known native American sites – Ancient tribes often used flint to make tools, weapons, and jewelry. If you know an area is historically associated with native activities, you can start by identifying possible settlement areas where flint deposits or tools were left behind. Some of the most promising areas include around caves and plains with huge gravel deposits or along paths used by these tribes.
  • Investigate natural water sources – If flint doesn’t occur naturally on the ground in the area, consider mapping out areas with water sources (rivers, streams, lakes or oceans) and search there. Walk along the beach, riverbanks or stream while looking for hard, glassy rocks. You are more likely to find flint alongside water bodies than any other areas.
  • Explore quarries – Flint/chert is a sedimentary rock that can be found in areas where sand, limestone, gem, chalk, and other minerals have been mined. See if there is an area near you with historic mines and defunct quarries. There’s a good chance you can find flint there.
  • Crack open some boulders – Flint also occurs in the form of nodule inside huge rocks. If the area has huge limestone and chalks rocks, use an iron hammer to break them open and find look for flint inside. If you see sparks when your hammer hits the rock, it’s possible that you will find flint within the rock. It occurs as hard rock with a darker shade than the surrounding limestone

Beyond just knowing where to look, it is important that you understand flint properties and characteristics. After all, besides exercise and fun, there’s no reason to go on a flint search when you don’t even know what it looks like.

Step 2: Learn to Identify Flint

First off, let’s clear something up. Sometimes you will hear people refer to flint-knapping or “fire-making” rocks as chert. So what is chert and what is flint? Is there even a difference? It depends on who you talk to:

  • If you talk to a Geologist, he or she will likely tell you that flint is a type of chert that is found in “chalk” or “marly” limestone.
  • If you talk to a flintknapper or anyone that works with rocks, you might be told that flint is of higher quality than chert.

For the purposes of this guide, I will refer to any chert rock that can make fire as flint. Reason being, any true chert can be used to make a fire.

What Does Flint Look Like?

There are a number of ways to identify flint based on the characteristics of the rock. Keep in mind that these characteristics will vary depending on the geographic location and chemical composition of the rock.

You can identify Flintstones by looking at:

  • Color – The least accurate way to test flint
  • Shape – Flint occurs as rounded nodules or (sometimes sharp) fractured stones
  • Hardness – Flint is very hard but brittle
  • Tenacity (grip-ability) – While glass-like, flint is almost never slippery and is easy to hold onto
  • Texture and Luster – Once broken from the nodule, flint is glossy and often has a waxy appearance
  • Streak and Transparency – The surface of flint often has streaks and is opaque/translucent

Let’s have a look at each of these properties and the different variations of flint according to specific characteristics.


It is important for you to understand the color of the flint found in a particular place. You wouldn’t want to be searching for brightly-colored flint in locations where only dark-pigmented versions exist.

Flint does not have a specific color. However, before being extracted from limestone and broken up, flint nodules typically have a thin, white outer layer with a rough texture and glossy surface called a cortex. The inside will typically have a glossy appearance.

Colors can range from gray, gold, brown, yellow, red, white, or even pink. Variations occur because of the inclusions of organic compounds, metal sulfides, and metal oxides & hydroxides.

If flint was formed with organic compounds and metal sulfides, it is likely to be dark grey or black in color. If formed with metal oxides and hydroxides, it is usually a brighter color like orange, yellow, gold, brown, or even red.

Places with high concentrations of organic compounds, like Connecticut, Ohio, and other states across the USA, have large deposits of dark gray and black flint – similar to the one shown below.

Photo courtesy of James St. John

In places with metal oxide and hydroxide concentrates, like England, Poland, and other parts of Europe, the flint has brighter colors (yellow, brown, gold, red, or white) – similar to the one shown below.

Shape and Size

Flint occurs either as nodules or in the form of fragments with different shapes and sizes.

  • Fractured flint has sharp edges and curves and is mostly found among gravel or under bigger rocks along riverbanks and beaches.
  • Round-shaped flint nodules have smooth edges and are bigger in size than fractured varieties. They are commonly found inside chalk or limestone rocks and occur in different colors from the limestone or chalk rock where they are found.


Mineral hardness is measured using the Mohs scale. Flint is rated 6.5-7 on the scale. To give you some perspective, talc is a 1 on the Mohs scale, and Diamond is a 10. Flint is hard enough that it can scratch glass.


Tenacity is the ability to grip something firmly without slipping. Flint has a brittle tenacity. This means that you can usually hold flint in your hand without it slipping.

However, this test is for dry flint found on the ground, among gravel, or buried in limestone or chalk. Stones from water bodies can be slippery.

While hard, most flint varieties can fracture easily when struck at the right angle with a hammerstone.

Texture and Luster

Flint has a smooth, glossy texture and a waxy, glossy luster. If you find flint along or inside water bodies, it is likely to have a smooth texture and glossy luster. If you find it in gravel, sand, limestone, or chalk, it may be covered in debris with a glossy texture and waxy luster.

If you are not sure of the rock you have in your hands, simply rub it using sand, and if it reveals a glassy luster and texture, you have got yourself a fire-making rock.

Streak and Transparency

Flint occurs in varying streaks (white, brown, or black) depending on the chemical composition of the location where you find it. Streaks are lines that form along with the stone where the compounds reacted and came together to form the rock.

Flint found in areas with metal oxide and hydroxide concentration has a brown or white streak, whereas the one found in places concentrated with organic compounds has white or dark-colored streaks.

Transparency is uniform in most types of flint. Most varieties come with an opaque/translucent look that turns shiny when polished. Although most have shiny insides, nodules can be dull and translucent.

Now you have a basic understanding of what flint looks like. Your first time out scouring the landscape, I recommend focusing solely on the hunt. Each time you think you have a possible flint rock, bag it and move on. Wait until you have a half dozen or so before you take a break to test them out to see if they actually are flint.

Step #3: Test Rocks to See If They Are Flint

Once you have gathered a few “candidates” that you think might be flint, there are a few tried and true tests that can be done to confirm or reject a rock:

  1. The scratch test – Flint is much harder than most other rocks. You can identify it by rubbing it against glass (take a bottle with you). If the rock scratches the glass, there’s a good chance that it is flint.
  2. The sound test – You can also identify flint through the sound it makes when you strike it against other hard rocks, metals, or surfaces. When you strike it against another rock or steel, flint produces a sharp “clink” (Click link to hear the sound), whereas other rocks produce a dull sound.
  3. The spark test – You can identify flint by striking it against another flint or steel. If you get sparks, then you probably just found what you are looking for. When using this technique, make sure that the edges of the stone are sharp and dry. This won’t work well on an unbroken nodule.
  4. The shard test – If you think you might have a nodule, you can carefully break off a piece of the stone with a hammer or a hammerstone. If the shard has a sharp edge, you probably have found flint. Be sure to wear thick gloves when you try this since it can be razor-sharp.

Once you have found flint, you may need to do some work on it before attempting to use it to make a fire.

Step #4: Process Your Flint

Once you identify and collect flint, you need to prepare it first before using it to make fire. Many beginners go straight to making fire immediately after finding flint, but this is not the best approach.

Regardless of where you find flint, it is likely to be covered in debris or cortex. If this is the case, hitting the rock to produce sparks is inefficient and will needlessly complicate the fire-making exercise.

Therefore, you need to clean and dry your flint before using it to make a fire. That way it is easy to strike and produces many sparks making it easy and fast to make fire.

Warning: There is a reason people have made weapons out of flint in the past. When fractured, flint has razer sharp edges. So make sure that you wear gloves and glasses to prevent injury to your hands or eyes during processing. We definitely don’t want to have to break out the first aid kit on our fire-making adventure.

Cleaning off the Cortex and Debris

The most common form of debris that covers any kind of chert is sand, soil, or cortex (quartz in powder form). There are a couple of ways to prepare flint for fire-making. You can either scrub and clean it to reveal a striking surface, or you can just break off pieces and use the shards.

The cleaning method

If your flint is covered with cortex, use water and a wire brush to clean it. Never use acid on your rocks since most of the debris won’t dissolve in acid anyway.

Once your rock is sparkling clean, wipe it with a dry cloth and leave it to dry under the sun. If the weather is wet and cold, you can dry it by covering it with a dry cloth or placing it inside your pocket to dry. Always use dry flint to produce sparks because it helps you save time and energy in the end.

If your rock is covered in hard soil or sand that doesn’t come off after washing, you can use sandpaper to wipe off the hard, attached sand or soil grains.

The fracturing method

This is probably the easiest way to ensure you get a clean striking surface to use during fire-making. However, it takes a fairly large piece of flint to start with. If you only have small shards, you will want to use the cleaning method.

  1. First, wearing gloves and protective glasses, hold the stone against a rock or your thigh (have thick pants or lay it in a cloth) at about a 30-degree angle from where you will be striking.
  2. Using a hammer or hammerstone, strike lightly about a half-inch back from the edge. You will want to strike the stone with the grain in order to create flakes. If you are unsure where the grain is, just strike it at the widest part of the rock. The flakes will break off with the grain.

Several shards will usually break off each time the stone fractures. You are trying to create fragments that are ideally about 2-3 inches long and an inch wide. However, slightly smaller or larger pieces are still usable.

Here is a useful video showing how to break flint up into smaller pieces:

You now have useable fire-making flint! So, let’s get to it.

Step #5: Making a Fire with the Flint You’ve Found

You’ve already done the hard part. Using a flint is easy if you follow the following steps:


  • A flint rock
  • A piece of steel, a pocket knife works great.
  • Kindling to start the fire (dry grass, paper, cardboard, or small dry twigs).
  • Large kindling to keep the fire burning (small sticks and logs).

Preparing your kindling:

  1. Make a small pile of dry twigs in an open area without trees or brush nearby that could catch fire.
  2. Place some kindling on top, almost like a bed. Dry grass works great, but you can use any other dry kindling.
  3. Put some more twigs on top, just for good measure. Make sure the bed is easy to pick up without falling apart.

Light the fire:

  1. Point the flint down over the bed, so the sparks fall into the kindling.
  2. Take the piece of steel or pocketknife and scratch down the flint towards the bed. Keep scraping sparks into the kindling until you see a small flame. This may take quite a few swipes.
  3. If the kindling is really dry and lights easily, go ahead and start adding more twigs. Add bigger and bigger sticks as the fire grows. If the fire isn’t starting easily and only smoke appears to be forming, try step 4.
  4. Once you see smoke, pick up the bed and hold it a few inches from your mouth. Blow until a fire starts. Quickly set down the bed and start feeding the fire with more kindling. Repeat steps 3 and 4 until you have a raging fire going.

That is it. You made fire with flint!

Here is a short video showing the process:

Don’t get discouraged if you either take a long time or completely fail your first time making a fire. As with anything, practice makes perfect. A lot of the time, it’s just that your kindling is either damp or too green to make a fire, so check that first.

What If I Don’t Have Steel?

If you don’t have a pocket knife or other piece of steel, you can still make sparks by using two pieces of flint. While this will generally not make sparks as well as flint and steel, it’s still a viable option.

Related Questions

Where do flint sparks come from? When fresh and pure iron particles are scraped off of the steel and flint, oxygen in the air causes the particles to ignite. This is because pure iron is “pyrophoric,” which means that it will spontaneously combust below 70°F (21°C).

What are some other names for flint? Other common names for flint or chert include silex, hornstone, flintstone, and firestone and the term depends on your location. Also, the name will vary based on your country. In Spain, flint is known as silex pedernal. The Dutch refer to it as vuursteen whereas Germans call it Feuerstein.

Are there any stone alternatives to flint? Any rock with high silica content can be used to make a fire. This includes any stone in the “flint family,” such as quartz, chert, jasper, or agate. Sometimes other types of rock can also make a spark. The best way to find out is to try rubbing a pocket knife down the face of a stone. If it sparks, you are in business.

For more, check out 4 Steps to Building the Best Fire Pits in Survival Shelters.