Octahedral fluorite is prized by collectors for its sharp geometric form, often resulting from the cleavage of larger cubic crystals. It frequently displays intense zoning or color-shifting properties and is highly valued when found with sharp edges and clear transparency.

Hardness
4
Mohs
Luster
Vitreous
Streak
White
Transparency
Transparent

Is this octahedral fluorite?

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 octahedral fluorite with a known reference. Octahedral Fluorite sits at Mohs 4 — softer than the next harder reference, harder than the previous one.
  • 2
    Check the streak
    Drag the specimen across an unglazed porcelain plate. Octahedral Fluorite leaves a white streak.
  • 3
    Read the luster
    Hold the specimen under a strong light. Octahedral Fluorite typically shows a vitreous luster.
  • 4
    Match the color range
    Compare against the expected color range: purple, blue, green, yellow, colorless, pink.
  • 5
    Look at form & habit
    Crystal system: isometric. Typical habit: octahedral.

Often confused with

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

Often found alongside octahedral fluorite

Minerals reported to co-occur with octahedral 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
3.18 g/cm³
Streak
White
Luster
Vitreous
Transparency
Transparent
Crystal system
Isometric
Crystal habit
Octahedral
Cleavage
Perfect Octahedral
Fluorescence
Often Fluorescent Blue or White Under UV Light
Rarity
Common
Uses
Collector, Lapidary
Host rock
Hydrothermal Veins, Limestone Cavities
Typical price
$10-100 for cabinet specimens, higher for large perfection

Where rockhounds find octahedral fluorite

Classic worldwide localities

  • Cave-in-Rock, Illinois, USA
  • Weardale, England
  • Asturias, Spain
  • Minas Gerais, Brazil

Field-hunting tip

Look in hydrothermal veins, limestone cavities country — that is the host setting where octahedral fluorite typically forms. If you start seeing quartz, galena, sphalerite in float, you are in the right ground. Field specimens usually show a octahedral habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify octahedral fluorite?+
Mohs hardness is 4. It typically shows a vitreous luster. The streak is white. Common colors include purple, blue, green, yellow.
Where is octahedral fluorite found?+
Notable localities include Cave-in-Rock, Illinois, USA; Weardale, England; Asturias, Spain; Minas Gerais, Brazil.
How much is octahedral fluorite worth?+
Typical asking prices fall in the range of $10-100 for cabinet specimens, higher for large perfection. Quality, size, and provenance can move individual specimens well outside that range.
What rocks look like octahedral fluorite?+
Octahedral Fluorite is most often confused with Halite, Calcite. A quick hardness test and a streak check separate the look-alikes faster than color alone.
What minerals are found with octahedral fluorite?+
Octahedral Fluorite commonly co-occurs with Quartz, Galena, Sphalerite, Barite. Spotting any of these in float or country rock is a useful trip signal.
What kind of rock does octahedral fluorite form in?+
Octahedral Fluorite typically forms in hydrothermal veins, limestone cavities. Working float back to the host body is the standard way to chase a fresh occurrence.
What is octahedral fluorite used for?+
Octahedral Fluorite is used in collector, lapidary.

Find octahedral fluorite on the map

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