Larsenite is an extremely rare lead-zinc silicate known almost exclusively from the famous Franklin and Sterling Hill mines in New Jersey. It is most easily identified by its brilliant yellow fluorescence under shortwave ultraviolet light. Collectors should look for it in association with other characteristic fluorescent minerals from the Franklin mining district.
Is this larsenite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch larsenite with a known reference. Larsenite sits at Mohs 3 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Larsenite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Larsenite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: white, colorless, yellowish-white.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: prismatic to acicular crystals, often as fibrous aggregates.
Often confused with
Larsenite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside larsenite
Minerals reported to co-occur with larsenite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- PbZnSiO₄
- Mohs hardness
- 3
- Density
- 5.9-6.0 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Orthorhombic
- Crystal habit
- Prismatic to Acicular Crystals, Often as Fibrous Aggregates
- Cleavage
- Good
- Fluorescence
- Bright Yellow Under SW UV
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Metamorphosed Zinc Ore Deposits
- Typical price
- $50-500 depending on size and quality
Where rockhounds find larsenite
Classic worldwide localities
- Franklin, New Jersey, USA
- Sterling Hill, New Jersey, USA
Field-hunting tip
Look in metamorphosed zinc ore deposits country — that is the host setting where larsenite typically forms. If you start seeing willemite, franklinite, zincite in float, you are in the right ground. Field specimens usually show a prismatic to acicular crystals, often as fibrous aggregates habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify larsenite?+
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How much is larsenite worth?+
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What rocks look like larsenite?+
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Find larsenite on the map
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