Aramayoite is a rare silver-antimony sulfosalt known primarily from its type locality in the silver-tin mines of Bolivia. It typically occurs as opaque, black to metallic gray tabular crystals and is highly prized by mineral collectors specializing in rare sulfosalts.

Hardness

2.5

Mohs

Luster

Metallic

Streak

Black

Transparency

Opaque

mineralrare

Aramayoite

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

Is this aramayoite?

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 aramayoite with a known reference. Aramayoite sits at Mohs 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. Aramayoite leaves a black streak.
3
Read the luster
Hold the specimen under a strong light. Aramayoite typically shows a metallic luster.
4
Match the color range
Compare against the expected color range: black, gray.
5
Look at form & habit
Crystal system: triclinic. Typical habit: tabular crystals, massive.

Often confused with

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

mineral

Miargyrite

Mohs 2.5

How to tell apart: Streak differs — Aramayoite leaves black, Miargyrite leaves cherry-red; luster reads metallic on Aramayoite and metallic to submetallic on Miargyrite.

Often found alongside aramayoite

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

All properties

Chemical formula: Ag₃(Sb,Bi)₂S₄
Mohs hardness: 2.5
Density: 5.62 g/cm³
Colors: Black Gray
Streak: Black
Luster: Metallic
Transparency: Opaque
Crystal system: Triclinic
Crystal habit: Tabular Crystals, Massive
Cleavage: Perfect Basal
Rarity: Rare
Uses: Collector, Scientific Research
Host rock: Hydrothermal Silver-tin Veins
Typical price: $50-500 depending on specimen size and rarity

Where rockhounds find aramayoite

Classic worldwide localities

Chocaya, Potosí, Bolivia
Tasna, Potosí, Bolivia

Field-hunting tip

Look in hydrothermal silver-tin veins country — that is the host setting where aramayoite typically forms. If you start seeing argyrodite, galena, pyrite in float, you are in the right ground. Field specimens usually show a tabular crystals, massive habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify aramayoite?+

Mohs hardness is 2.5. It typically shows a metallic luster. The streak is black. Common colors include black, gray.

Where is aramayoite found?+

Notable localities include Chocaya, Potosí, Bolivia; Tasna, Potosí, Bolivia.

How much is aramayoite worth?+

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

Is aramayoite safe to handle?+

It contains toxic constituents. Contains silver, antimony, and sulfur; handle with care to avoid ingestion or inhalation of dust. Wash hands thoroughly after handling. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like aramayoite?+

Aramayoite is most often confused with Miargyrite, Schapbachite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with aramayoite?+

Aramayoite commonly co-occurs with Argyrodite, Galena, Pyrite, Siderite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does aramayoite form in?+

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

What is aramayoite used for?+

Aramayoite is used in collector, scientific research.

Find aramayoite on the map

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