Jalpaite is a rare silver-copper sulfide that typically appears as lead-gray to black anhedral masses within hydrothermal veins. It is most commonly found in association with acanthite and stromeyerite, often requiring X-ray diffraction or chemical analysis for positive identification due to its unremarkable appearance.
Is this jalpaite?
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 jalpaite with a known reference. Jalpaite sits at Mohs 2-2.5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Jalpaite leaves a black streak.
- 3Read the lusterHold the specimen under a strong light. Jalpaite typically shows a metallic luster.
- 4Match the color rangeCompare against the expected color range: lead-gray, iron-black.
- 5Look at form & habitCrystal system: tetragonal. Typical habit: massive, anhedral grains.
Often confused with
Jalpaite vs. its common look-alikes — and how to tell them apart in the field.


How to tell apart: Streak differs — Jalpaite leaves black, Stromeyerite leaves dark gray.

How to tell apart: Chalcopyrite is the harder of the two (Mohs 3.5-4 vs. 2-2.5); streak differs — Jalpaite leaves black, Chalcopyrite leaves greenish-black.
Often found alongside jalpaite
Minerals reported to co-occur with jalpaite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ag₃CuS₂
- Mohs hardness
- 2-2.5
- Density
- 6.83 g/cm³
- Colors
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Tetragonal
- Crystal habit
- Massive, Anhedral Grains
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Hydrothermal Vein Deposits
- Typical price
- $50-300 per specimen
Where rockhounds find jalpaite
Classic worldwide localities
- Jalpa, Mexico
- Freiberg, Germany
- Guanajuato, Mexico
- Broken Hill, Australia
Field-hunting tip
Look in hydrothermal vein deposits country — that is the host setting where jalpaite typically forms. If you start seeing acanthite, stromeyerite, pyrite in float, you are in the right ground. Field specimens usually show a massive, anhedral grains habit, so train your eye for that shape before scanning the outcrop.



