Flint is a hard, cryptocrystalline form of quartz that commonly occurs as nodules in sedimentary rocks like chalk. It is famous for its conchoidal fracture, which creates razor-sharp edges used historically for tools and fire-starting.

Hardness

Mohs

Luster

Waxy

Streak

White

Transparency

Translucent

mineralcommonQuartz family

Flint

Also: chert

Hardness: 7
Luster: Waxy
Streak: White
Transparency: Translucent

Is this flint?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

1
Test the hardness
Try to scratch flint with a known reference. Flint sits at Mohs 7 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Flint leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Flint typically shows a waxy luster.
4
Match the color range
Compare against the expected color range: gray, black, brown, white.
5
Look at form & habit
Crystal system: trigonal. Typical habit: massive.

Often confused with

Flint vs. its common look-alikes — and how to tell them apart in the field.

Often found alongside flint

Minerals reported to co-occur with flint. Spotting these in float or country rock is a strong cue you are in the right ground.

All properties

Chemical formula: SiO₂
Mohs hardness: 7
Density: 2.6 g/cm³
Colors: Gray Black Brown White
Streak: White
Luster: Waxy
Transparency: Translucent
Crystal system: Trigonal
Crystal habit: Massive
Cleavage: None
Rarity: Common
Uses: Lapidary, Historical Toolmaking, Decorative
Host rock: Sedimentary Environments Within Chalk and Limestone Formations
Typical price: $5-20 per specimen

Where rockhounds find flint

16 mapped spots

Classic worldwide localities

United Kingdom
France
Denmark
United States
Poland

U.S. states with flint

Each link opens a state-specific list of mapped rockhounding spots that produce flint.

Ohio6 spots

Field-hunting tip

Look in sedimentary environments within chalk and limestone formations country — that is the host setting where flint typically forms. If you start seeing chalk, limestone in float, you are in the right ground. Field specimens usually show a massive habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Ohio, Nevada, Florida — start trip planning there.

Browse 16 U.S. spots for flint →

Common questions

How do you identify flint?+

Mohs hardness is 7. It typically shows a waxy luster. The streak is white. Common colors include gray, black, brown, white.

Where is flint found?+

Notable localities include United Kingdom; France; Denmark; United States; Poland.

Can I find flint in the United States?+

RockHoundR maps 16 flint rockhounding spots across 9 U.S. states — the top states are Ohio, Nevada, Florida.

How much is flint worth?+

Typical asking prices fall in the range of $5-20 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like flint?+

Flint is most often confused with Flint Nodules, Jasper, Chalcedony. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with flint?+

Flint commonly co-occurs with Chalk, Limestone. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does flint form in?+

Flint typically forms in sedimentary environments within chalk and limestone formations. Working float back to the host body is the standard way to chase a fresh occurrence.

What is flint used for?+

Flint is used in lapidary, historical toolmaking, decorative.

Find flint on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.