Fluorite is prized by collectors for its stunning range of vibrant colors and well-defined cubic or octahedral crystals. It is easily identified by its perfect octahedral cleavage and relative softness, making it a staple in any mineral collection.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralcommon

Fluorite

Also: Fluorspar

Hardness: 4
Luster: Vitreous
Streak: White
Transparency: Transparent

Spotting fluorite in the field

Field marks

1
Cubes, and often cubes stacked on cubes, in purple, green, blue or yellow
2
Four perfect cleavage directions, so broken corners come away as neat triangles
3
Soft at 4, so a knife marks it easily, and many specimens glow under ultraviolet light

Cubes plus softness settles it. If it forms cubes and a steel point marks it, it is fluorite rather than quartz, and the octahedral cleavage means damaged corners break off as little pyramids rather than chipping randomly. It occurs in hydrothermal veins and in limestone, and the Illinois-Kentucky district around Cave in Rock and Marion produced the finest American material. Fluorite gave fluorescence its name, so a UV light is worth carrying, though not every specimen glows.

Straight answers

Is it worth cutting?: Too soft and too cleavable for jewelry that gets worn. It is carved and cut as display pieces, and Blue John from Derbyshire is the famous banded ornamental variety.
What is it really worth?: Inexpensive as material. Sharp lustrous crystal groups, unusual colors and strong fluorescence are the collector value, and Illinois specimens have a following.
Can you legally keep it?: The Illinois-Kentucky mines are closed as commercial operations, but there are established fee-dig opportunities and a museum-run collecting site in the district.

Where it is worth going

Illinois-Kentucky fluorspar district
Around Cave in Rock, Illinois and Marion, Kentucky
Fluorite is the Illinois state mineral. Mines are closed, but organized fee digging on dumps is available.

Often confused with

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

mineral

Quartz

Mohs 7

How to tell apart: Quartz forms six-sided prisms, is hardness 7 and has no cleavage. Fluorite forms cubes, is hardness 4 and cleaves perfectly.

How to tell apart: Calcite is softer at 3, cleaves into rhombs rather than octahedra, and fizzes in dilute acid. Fluorite does not fizz.

How to tell apart: Purple fluorite is often mistaken for amethyst. Hardness and cleavage separate them instantly.

Compare →

Side by side:Fluorite vs Amethyst

Often found alongside fluorite

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

All properties

Chemical formula: CaF₂
Mohs hardness: 4
Density: 3.1-3.2 g/cm³
Colors: Purple Blue Green Yellow Colorless White Pink
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Cubic
Crystal habit: Cubic Crystals, Octahedral, Dodecahedral, Massive
Cleavage: Perfect Octahedral
Fluorescence: Often Strongly Fluorescent Blue or Violet Under UV Light
Rarity: Common
Uses: Collector, Industrial, Lapidary, Flux
Host rock: Hydrothermal Veins, Sedimentary Limestone, Pegmatites
Typical price: $5-50 thumbnail, $50-500 cabinet specimen

Where rockhounds find fluorite

124 mapped spots

Classic worldwide localities

Cave-in-Rock, Illinois, USA
Weardale, England
Asturias, Spain
Okorusu, Namibia
Hunan, China

U.S. states with fluorite

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

Field-hunting tip

Look in hydrothermal veins, sedimentary limestone, pegmatites country, the host setting where fluorite typically forms. If you start seeing calcite, quartz, galena in float, you are in the right ground. Field specimens usually show a cubic crystals, octahedral, dodecahedral, massive habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Utah, New Mexico, Kentucky. Start trip planning there.

Browse 124 U.S. spots for fluorite →

Common questions

How do you identify fluorite?+

Mohs hardness is 4. It typically shows a vitreous luster. The streak is white. Common colors include purple, blue, green, yellow.

Where is fluorite found?+

Notable localities include Cave-in-Rock, Illinois, USA; Weardale, England; Asturias, Spain; Okorusu, Namibia; Hunan, China.

Can I find fluorite in the United States?+

RockHoundR maps 124 fluorite rockhounding spots across 12 U.S. states. The top states are Utah, New Mexico, Kentucky.

How much is fluorite worth?+

Typical asking prices fall in the range of $5-50 thumbnail, $50-500 cabinet specimen. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like fluorite?+

Fluorite is most often confused with Quartz, Calcite, Amethyst. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with fluorite?+

Fluorite commonly co-occurs with Calcite, Quartz, Galena, Sphalerite, Barite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does fluorite form in?+

Fluorite typically forms in hydrothermal veins, sedimentary limestone, pegmatites. Working float back to the host body is the standard way to chase a fresh occurrence.

What is fluorite used for?+

Fluorite is used in collector, industrial, lapidary, flux.

Find fluorite on the map

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