Carobbiite is a rare potassium fluoride mineral typically found as small, colorless crystals in volcanic environments or pegmatites. It is highly water-soluble and can be easily confused with halite or sylvite, though it is usually distinguished by its specific formation environment and chemical tests.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Carobbiite

Hardness: 2
Luster: Vitreous
Streak: White
Transparency: Transparent

Is this carobbiite?

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 carobbiite with a known reference. Carobbiite sits at Mohs 2 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Carobbiite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Carobbiite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: colorless, white.
5
Look at form & habit
Crystal system: cubic. Typical habit: octahedral, massive, granular.

Often confused with

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

Often found alongside carobbiite

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

All properties

Chemical formula: KF
Mohs hardness: 2
Density: 1.99 g/cm³
Colors: Colorless White
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Cubic
Crystal habit: Octahedral, Massive, Granular
Cleavage: Perfect Cubic
Rarity: Rare
Uses: Collector
Host rock: Volcanic Fumaroles, Pegmatites
Typical price: $50-300 per specimen

Where rockhounds find carobbiite

Classic worldwide localities

Vesuvius, Italy
Khibiny Massif, Russia
Sar-e-Sang, Afghanistan

Field-hunting tip

Look in volcanic fumaroles, pegmatites country — that is the host setting where carobbiite typically forms. If you start seeing fluorite, sylvite, halite in float, you are in the right ground. Field specimens usually show a octahedral, massive, granular habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify carobbiite?+

Mohs hardness is 2. It typically shows a vitreous luster. The streak is white. Common colors include colorless, white.

Where is carobbiite found?+

Notable localities include Vesuvius, Italy; Khibiny Massif, Russia; Sar-e-Sang, Afghanistan.

How much is carobbiite worth?+

Typical asking prices fall in the range of $50-300 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

Is carobbiite safe to handle?+

It contains toxic constituents. Contains fluorine and can be toxic if ingested or inhaled as dust; handle with care and wash hands thoroughly after contact. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like carobbiite?+

Carobbiite is most often confused with Halite, Sylvite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with carobbiite?+

Carobbiite commonly co-occurs with Fluorite, Sylvite, Halite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does carobbiite form in?+

Carobbiite typically forms in volcanic fumaroles, pegmatites. Working float back to the host body is the standard way to chase a fresh occurrence.

What is carobbiite used for?+

Carobbiite is used in collector.

Find carobbiite on the map

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