Ephesite is a rare brittle mica that typically occurs as thin, platy crystals or foliated masses. It is primarily identified by its occurrence in specific metamorphic environments like emery deposits and its distinct association with corundum and diaspore.

Hardness

3.5-4

Mohs

Luster

Pearly

Streak

White

Transparency

Translucent

mineralrareMica Group family

Ephesite

Hardness: 3.5-4
Luster: Pearly
Streak: White
Transparency: Translucent

Is this ephesite?

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 ephesite with a known reference. Ephesite sits at Mohs 3.5-4 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Ephesite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Ephesite typically shows a pearly luster.
4
Match the color range
Compare against the expected color range: white, pink, pale red, colorless.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: platy crystals, micaceous aggregates.

Often confused with

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

Often found alongside ephesite

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

All properties

Chemical formula: NaLiAl₂(Al₂Si₂)O₁₀(OH)₂
Mohs hardness: 3.5-4
Density: 3.06 g/cm³
Colors: White Pink Pale Red Colorless
Streak: White
Luster: Pearly
Transparency: Translucent
Crystal system: Monoclinic
Crystal habit: Platy Crystals, Micaceous Aggregates
Cleavage: Perfect Basal
Rarity: Rare
Uses: Collector
Host rock: Metamorphic Rocks, Specifically Emery Deposits and Metamorphosed Limestones
Typical price: $20-150 for thumbnail to small cabinet specimens

Where rockhounds find ephesite

Classic worldwide localities

Ephesus, Turkey
Franklin, New Jersey, USA
Jacupiranga, Brazil
Sar-e-Sang, Afghanistan

Field-hunting tip

Look in metamorphic rocks, specifically emery deposits and metamorphosed limestones country — that is the host setting where ephesite typically forms. If you start seeing corundum, diaspore, chlorite in float, you are in the right ground. Field specimens usually show a platy crystals, micaceous aggregates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify ephesite?+

Mohs hardness is 3.5-4. It typically shows a pearly luster. The streak is white. Common colors include white, pink, pale red, colorless.

Where is ephesite found?+

Notable localities include Ephesus, Turkey; Franklin, New Jersey, USA; Jacupiranga, Brazil; Sar-e-Sang, Afghanistan.

How much is ephesite worth?+

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

What rocks look like ephesite?+

Ephesite is most often confused with Margarite, Muscovite, Lepidolite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with ephesite?+

Ephesite commonly co-occurs with Corundum, Diaspore, Chlorite, Magnetite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does ephesite form in?+

Ephesite typically forms in metamorphic rocks, specifically emery deposits and metamorphosed limestones. Working float back to the host body is the standard way to chase a fresh occurrence.

What is ephesite used for?+

Ephesite is used in collector.

Find ephesite on the map

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