Lefontite is a rare member of the chlorite group, characterized by its iron-rich composition and distinct platy crystal habit. It is primarily found in metamorphic environments and is best identified through laboratory analysis given its strong resemblance to other common chlorite minerals.

Hardness

2.5

Mohs

Luster

Pearly

Streak

White

Transparency

Translucent

mineralrareChlorite Group family

Lefontite

Hardness: 2.5
Luster: Pearly
Streak: White
Transparency: Translucent

Is this lefontite?

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 lefontite with a known reference. Lefontite sits at Mohs 2.5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Lefontite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Lefontite typically shows a pearly luster.
4
Match the color range
Compare against the expected color range: green, yellowish-green.
5
Look at form & habit
Crystal system: triclinic. Typical habit: platy crystals.

Often confused with

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

How to tell apart: Streak differs — Lefontite leaves white, Chamosite leaves white to pale green.

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Often found alongside lefontite

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

All properties

Chemical formula: (Fe²⁺,Mg,Al)₆(Si,Al)₄O₁₀(OH)₈
Mohs hardness: 2.5
Density: 3.17 g/cm³
Colors: Green Yellowish-green
Streak: White
Luster: Pearly
Transparency: Translucent
Crystal system: Triclinic
Crystal habit: Platy Crystals
Cleavage: Perfect Basal
Rarity: Rare
Uses: Collector
Host rock: Metamorphic Schists
Typical price: $20-100 per specimen

Where rockhounds find lefontite

Classic worldwide localities

Lefont, France

Field-hunting tip

Look in metamorphic schists country — that is the host setting where lefontite typically forms. If you start seeing quartz, siderite, pyrite in float, you are in the right ground. Field specimens usually show a platy crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify lefontite?+

Mohs hardness is 2.5. It typically shows a pearly luster. The streak is white. Common colors include green, yellowish-green.

Where is lefontite found?+

Notable localities include Lefont, France.

How much is lefontite worth?+

Typical asking prices fall in the range of $20-100 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like lefontite?+

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

What minerals are found with lefontite?+

Lefontite commonly co-occurs with quartz, siderite, pyrite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does lefontite form in?+

Lefontite typically forms in metamorphic schists. Working float back to the host body is the standard way to chase a fresh occurrence.

What is lefontite used for?+

Lefontite is used in collector.

Find lefontite on the map

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