Krennerite is a rare gold-silver telluride that forms in low-temperature hydrothermal veins. It is distinguished from its dimorph, calaverite, by its orthorhombic crystal structure and distinct striated habit.
Is this krennerite?
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 krennerite with a known reference. Krennerite sits at Mohs 2.5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Krennerite leaves a yellowish-grey streak.
- 3Read the lusterHold the specimen under a strong light. Krennerite typically shows a metallic luster.
- 4Match the color rangeCompare against the expected color range: silver-white, pale brass-yellow.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: prismatic, striated, sometimes tabular or bladed.
Often confused with
Krennerite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Streak differs — Krennerite leaves yellowish-grey, Calaverite leaves yellowish-green.
How to tell apart: Streak differs — Krennerite leaves yellowish-grey, Sylvanite leaves gray.
How to tell apart: Streak differs — Krennerite leaves yellowish-grey, Petzite leaves iron-black.
Often found alongside krennerite
Minerals reported to co-occur with krennerite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Au,Ag)Te₂
- Mohs hardness
- 2.5
- Density
- 8.6-8.9 g/cm³
- Streak
- Yellowish-grey
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Orthorhombic
- Crystal habit
- Prismatic, Striated, Sometimes Tabular or Bladed
- Cleavage
- Good On {001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Epithermal Gold-telluride Veins
- Typical price
- $50-500 depending on crystal size and quality
Where rockhounds find krennerite
1 mapped spotsClassic worldwide localities
- Sacaramb, Romania
- Crippled Creek, Colorado, USA
- Kalgoorlie, Western Australia
- Kirkland Lake, Ontario, Canada
Field-hunting tip
Look in epithermal gold-telluride veins country — that is the host setting where krennerite typically forms. If you start seeing gold, pyrite, telluride minerals in float, you are in the right ground. Field specimens usually show a prismatic, striated, sometimes tabular or bladed habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Wisconsin — start trip planning there.
Common questions
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Find krennerite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
