Fluoro-cannilloite is an exceptionally rare member of the amphibole supergroup characterized by its fluorine-dominant site. It typically occurs as prismatic crystals within contact-metamorphosed limestone deposits and requires advanced analytical methods for positive identification.

Hardness

5-6

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrareAmphibole Supergroup family

Fluoro-cannilloite

Hardness: 5-6
Luster: Vitreous
Streak: White
Transparency: Translucent

No image

Is this fluoro-cannilloite?

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 fluoro-cannilloite with a known reference. Fluoro-cannilloite sits at Mohs 5-6, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: white.
3
Read the luster
Hold the specimen under a strong light. Luster: vitreous.
4
Match the color range
Compare against the expected color range: brown, yellow-brown.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: prismatic crystals.

Often confused with

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

mineral

Hastingsite

Mohs 5-6

How to tell apart: Streak differs, so Fluoro-cannilloite leaves white, Hastingsite leaves greenish gray.

Often found alongside fluoro-cannilloite

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

All properties

Chemical formula: CaCa₂(Mg₄Al)(Si₅Al₃)O₂₂F₂
Mohs hardness: 5-6
Colors: Brown Yellow-brown
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Monoclinic
Crystal habit: Prismatic crystals
Cleavage: Perfect in two directions
Rarity: Rare
Uses: Collector
Host rock: metamorphic limestones

Where rockhounds find fluoro-cannilloite

Classic worldwide localities

Pargas, Finland

Field-hunting tip

Where it forms: metamorphic limestones. If you start seeing calcite, diopside, phlogopite in float, you are in the right ground. Typical habit: prismatic crystals. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify fluoro-cannilloite?+

Mohs hardness is 5-6. Luster: vitreous. The streak is white. Common colors include brown, yellow-brown.

Where is fluoro-cannilloite found?+

Notable localities include Pargas, Finland.

What rocks look like fluoro-cannilloite?+

Fluoro-cannilloite is most often confused with Hastingsite, Edenite, Tremolite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with fluoro-cannilloite?+

Fluoro-cannilloite commonly co-occurs with Calcite, Diopside, Phlogopite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does fluoro-cannilloite form in?+

Where it forms: metamorphic limestones. Working float back to the host body is the standard way to chase a fresh occurrence.

What is fluoro-cannilloite used for?+

Fluoro-cannilloite is used in collector.

Find fluoro-cannilloite on the map

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