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.
Is this octahedral fluorite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry 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.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: purple, blue, green, yellow, colorless, pink.
- 5Look at form & habitCrystal system: cubic. 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
- Cubic
- 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
Where rockhounds find octahedral fluorite
Classic worldwide localities
- Cave-in-Rock, Illinois, USA
- Weardale, England
- Asturias, Spain
- Minas Gerais, Brazil
Field-hunting tip
Where it forms: hydrothermal veins, limestone cavities. If you start seeing quartz, galena, sphalerite in float, you are in the right ground. Typical habit: octahedral. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify octahedral fluorite?+
Where is octahedral fluorite found?+
What rocks look like octahedral fluorite?+
What minerals are found with octahedral fluorite?+
What kind of rock does octahedral fluorite form in?+
What is octahedral fluorite used for?+
Find octahedral fluorite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
