Torreyite is a rare secondary mineral typically found as small, yellow, platy or radiating crystals. It is most famous from the zinc mines of Franklin and Sterling Hill, New Jersey, where it forms in oxidized zones of ore bodies.

Hardness

2-3

Mohs

Luster

Pearly

Streak

White

Transparency

Translucent

mineralrare

Torreyite

Hardness: 2-3
Luster: Pearly
Streak: White
Transparency: Translucent

Is this torreyite?

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

Often confused with

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

How to tell apart: Luster reads pearly on Torreyite and dull on Hydrozincite.

Compare →

Often found alongside torreyite

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

All properties

Chemical formula: (Mg,Mn,Zn)₁₅(SO₄)₂(OH)₂₂·8H₂O
Mohs hardness: 2-3
Density: 2.84 g/cm³
Colors: Yellow Yellowish-orange
Streak: White
Luster: Pearly
Transparency: Translucent
Crystal system: Monoclinic
Crystal habit: Platy Crystals, Radial Aggregates, Crusts
Cleavage: Perfect On {001}
Rarity: Rare
Uses: Collector
Host rock: Metamorphosed Zinc Ore Deposits
Typical price: $50-300 per specimen

Where rockhounds find torreyite

Classic worldwide localities

Sterling Hill Mine, New Jersey, USA
Franklin Mine, New Jersey, USA
Långban, Sweden

Field-hunting tip

Look in metamorphosed zinc ore deposits country — that is the host setting where torreyite typically forms. If you start seeing zincite, willemite, franklinite in float, you are in the right ground. Field specimens usually show a platy crystals, radial aggregates, crusts habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify torreyite?+

Mohs hardness is 2-3. It typically shows a pearly luster. The streak is white. Common colors include yellow, yellowish-orange.

Where is torreyite found?+

Notable localities include Sterling Hill Mine, New Jersey, USA; Franklin Mine, New Jersey, USA; Långban, Sweden.

How much is torreyite 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.

What rocks look like torreyite?+

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

What minerals are found with torreyite?+

Torreyite commonly co-occurs with Zincite, Willemite, Franklinite, Hancockite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does torreyite form in?+

Torreyite typically forms in metamorphosed zinc ore deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is torreyite used for?+

Torreyite is used in collector.

Find torreyite on the map

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