Cylindrite is a fascinating sulfosalt mineral notable for its unique cylindrical or tubular crystal habit, often looking like tiny rolled-up scrolls or pipes. It is primarily found in the tin-silver deposits of the Oruro and Potosí departments of Bolivia. Collectors prize well-defined cylindrical specimens for their unusual morphology.

Hardness

2-2.5

Mohs

Luster

Metallic

Streak

Black

Transparency

Opaque

mineralrareSulfide Mineral family

Cylindrite

Hardness: 2-2.5
Luster: Metallic
Streak: Black
Transparency: Opaque

Is this cylindrite?

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 cylindrite with a known reference. Cylindrite sits at Mohs 2-2.5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Cylindrite leaves a black streak.
3
Read the luster
Hold the specimen under a strong light. Cylindrite typically shows a metallic luster.
4
Match the color range
Compare against the expected color range: dark lead-gray, blackish-gray.
5
Look at form & habit
Crystal system: triclinic. Typical habit: cylindrical aggregates, tubular crystals, flexible lamellae.

Often confused with

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

How to tell apart: Streak differs — Cylindrite leaves black, Jamesonite leaves gray-black.

Often found alongside cylindrite

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

All properties

Chemical formula: Pb₃Sn₄FeSb₂S₁₄
Mohs hardness: 2-2.5
Density: 5.4-5.5 g/cm³
Colors: Dark Lead-gray Blackish-gray
Streak: Black
Luster: Metallic
Transparency: Opaque
Crystal system: Triclinic
Crystal habit: Cylindrical Aggregates, Tubular Crystals, Flexible Lamellae
Cleavage: Perfect On {001}
Rarity: Rare
Uses: Collector, Scientific Research
Host rock: Hydrothermal Tin-silver Veins
Typical price: $50-500 thumbnail depending on cylinder perfection

Where rockhounds find cylindrite

Classic worldwide localities

Poopó, Oruro, Bolivia
Chocaya, Potosí, Bolivia
San José mine, Oruro, Bolivia

Field-hunting tip

Look in hydrothermal tin-silver veins country — that is the host setting where cylindrite typically forms. If you start seeing franckeite, galena, cassiterite in float, you are in the right ground. Field specimens usually show a cylindrical aggregates, tubular crystals, flexible lamellae habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify cylindrite?+

Mohs hardness is 2-2.5. It typically shows a metallic luster. The streak is black. Common colors include dark lead-gray, blackish-gray.

Where is cylindrite found?+

Notable localities include Poopó, Oruro, Bolivia; Chocaya, Potosí, Bolivia; San José mine, Oruro, Bolivia.

How much is cylindrite worth?+

Typical asking prices fall in the range of $50-500 thumbnail depending on cylinder perfection. Quality, size, and provenance can move individual specimens well outside that range.

Is cylindrite safe to handle?+

It contains toxic constituents. Contains lead, antimony, and sulfur; wash hands thoroughly after handling and avoid inhaling dust. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like cylindrite?+

Cylindrite is most often confused with Franckeite, Jamesonite, Teallite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with cylindrite?+

Cylindrite commonly co-occurs with Franckeite, Galena, Cassiterite, Stannite, Sphalerite, Pyrite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does cylindrite form in?+

Cylindrite typically forms in hydrothermal tin-silver veins. Working float back to the host body is the standard way to chase a fresh occurrence.

What is cylindrite used for?+

Cylindrite is used in collector, scientific research.

Find cylindrite on the map

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