Kësterite is a rare copper zinc tin sulfide mineral typically found in tin-bearing hydrothermal deposits. It is often indistinguishable from stannite in hand samples without laboratory analysis, generally appearing as opaque, dark metallic masses.
Is this kësterite?
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 kësterite with a known reference. Kësterite sits at Mohs 4.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: black.
- 3Read the lusterHold the specimen under a strong light. Luster: metallic.
- 4Match the color rangeCompare against the expected color range: greenish black.
- 5Look at form & habitCrystal system: tetragonal. Typical habit: massive, granular, or anhedral grains.
Often confused with
Kësterite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Kësterite leaves black, Stannite leaves blackish.
How to tell apart: Streak differs, so Kësterite leaves black, Sphalerite leaves pale brown to pale yellow and white; luster reads metallic on Kësterite and resinous to adamantine on Sphalerite.
How to tell apart: Streak differs, so Kësterite leaves black, Chalcopyrite leaves greenish black.
Often found alongside kësterite
Minerals reported to co-occur with kësterite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Cu₂ZnSnS₄
- Mohs hardness
- 4.5
- Density
- 4.54-4.59 g/cm³
- Colors
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Tetragonal
- Crystal habit
- Massive, granular, or anhedral grains
- Cleavage
- None
- Rarity
- Uncommon
- Uses
- Collector
- Host rock
- In quartz-sulfide hydrothermal veinlets in tin deposits
Where rockhounds find kësterite
Classic worldwide localities
- Hugo mine and in the Peerless pegmatite, near Keystone, Pennington Co., South Dakota, USA
- Cove mine, McCoy district, Lander Co., Nevada, USA
- Campbell mine, Bisbee, Cochise Co., Arizona, USA
- Kester deposit, Arga-Ynnakh-Khai granite massif, Yana-Adycha River region, Sakha, Russia (type locality)
- Kochbulak gold deposit, Chatkal-Kuramin Mountains, eastern Uzbekistan
- Dachang district, Guangxi Autonomous Region, China
Field-hunting tip
Where it forms: In quartz-sulfide hydrothermal veinlets in tin deposits. If you start seeing arsenopyrite, stannoidite, chalcopyrite in float, you are in the right ground. Typical habit: massive, granular, or anhedral grains. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify kësterite?+
Where is kësterite found?+
Is kësterite safe to handle?+
What rocks look like kësterite?+
What minerals are found with kësterite?+
What kind of rock does kësterite form in?+
What is kësterite used for?+
Find kësterite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
