Amesite is a relatively rare member of the chlorite group, typically occurring as small, pearly, pseudohexagonal plates. It is best identified by its association with altered ultramafic rocks and its distinct micaceous habit compared to more common chlorite species.

Hardness

2.5-3

Mohs

Luster

Pearly

Streak

White

Transparency

Translucent

mineralrareChlorite Group family

Amesite

Hardness: 2.5-3
Luster: Pearly
Streak: White
Transparency: Translucent

Is this amesite?

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

Often confused with

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

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

Often found alongside amesite

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

All properties

Chemical formula: Mg₂Al(SiAl)O₅(OH)₄
Mohs hardness: 2.5-3
Density: 2.7-2.9 g/cm³
Colors: White Green Pink Red
Streak: White
Luster: Pearly
Transparency: Translucent
Crystal system: Triclinic
Crystal habit: Pseudohexagonal Platy Crystals, Micaceous Aggregates
Cleavage: Perfect Basal
Rarity: Rare
Uses: Collector
Host rock: Metamorphic Rocks, Specifically Contact Metamorphic Zones and Hydrothermal Veins
Typical price: $20-150 thumbnail specimens

Where rockhounds find amesite

Classic worldwide localities

Chester, Massachusetts, USA
Sarany, Ural Mountains, Russia
Val di Vizze, Italy
Lac Nicolet, Quebec, Canada

Field-hunting tip

Look in metamorphic rocks, specifically contact metamorphic zones and hydrothermal veins country — that is the host setting where amesite typically forms. If you start seeing magnetite, calcite, diopside in float, you are in the right ground. Field specimens usually show a pseudohexagonal platy crystals, micaceous aggregates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify amesite?+

Mohs hardness is 2.5-3. It typically shows a pearly luster. The streak is white. Common colors include white, green, pink, red.

Where is amesite found?+

Notable localities include Chester, Massachusetts, USA; Sarany, Ural Mountains, Russia; Val di Vizze, Italy; Lac Nicolet, Quebec, Canada.

How much is amesite worth?+

Typical asking prices fall in the range of $20-150 thumbnail specimens. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like amesite?+

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

What minerals are found with amesite?+

Amesite commonly co-occurs with Magnetite, Calcite, Diopside, Dolomite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does amesite form in?+

Amesite typically forms in metamorphic rocks, specifically contact metamorphic zones and hydrothermal veins. Working float back to the host body is the standard way to chase a fresh occurrence.

What is amesite used for?+

Amesite is used in collector.

Find amesite on the map

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