Uytenbogaardtite is a rare silver gold sulfide that typically occurs as microscopic inclusions within other sulfide minerals. It is almost exclusively found in epithermal precious metal deposits and requires microscopic examination for positive identification.

Hardness

2.5

Mohs

Luster

Metallic

Streak

Black

Transparency

Opaque

mineralrare

Uytenbogaardtite

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

Is this uytenbogaardtite?

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 uytenbogaardtite with a known reference. Uytenbogaardtite 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. Uytenbogaardtite leaves a black streak.
3
Read the luster
Hold the specimen under a strong light. Uytenbogaardtite typically shows a metallic luster.
4
Match the color range
Compare against the expected color range: white, pale yellow.
5
Look at form & habit
Crystal system: tetragonal. Typical habit: microscopic grains, aggregates.

Often confused with

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

How to tell apart: Streak differs — Uytenbogaardtite leaves black, Petzite leaves iron-black.

Often found alongside uytenbogaardtite

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

All properties

Chemical formula: Ag₃AuS₂
Mohs hardness: 2.5
Density: 9.1 g/cm³
Colors: White Pale Yellow
Streak: Black
Luster: Metallic
Transparency: Opaque
Crystal system: Tetragonal
Crystal habit: Microscopic Grains, Aggregates
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Epithermal Gold-silver Veins
Typical price: expensive due to rarity

Where rockhounds find uytenbogaardtite

Classic worldwide localities

Uytenbogaardt mine, South Africa
Hope's Nose, England
Taimyr Peninsula, Russia
Guanajuato, Mexico

Field-hunting tip

Look in epithermal gold-silver veins country — that is the host setting where uytenbogaardtite typically forms. If you start seeing gold, acanthite, galena in float, you are in the right ground. Field specimens usually show a microscopic grains, aggregates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify uytenbogaardtite?+

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

Where is uytenbogaardtite found?+

Notable localities include Uytenbogaardt mine, South Africa; Hope's Nose, England; Taimyr Peninsula, Russia; Guanajuato, Mexico.

How much is uytenbogaardtite worth?+

Typical asking prices fall in the range of expensive due to rarity. Quality, size, and provenance can move individual specimens well outside that range.

Is uytenbogaardtite safe to handle?+

It contains toxic constituents. Contains silver and gold; handling precautions are standard for metallic sulfides, but caution is advised to avoid ingestion or inhalation of dust. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like uytenbogaardtite?+

Uytenbogaardtite is most often confused with Acanthite, Petzite, Hessite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with uytenbogaardtite?+

Uytenbogaardtite commonly co-occurs with Gold, Acanthite, Galena, Chalcopyrite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does uytenbogaardtite form in?+

Uytenbogaardtite typically forms in epithermal gold-silver veins. Working float back to the host body is the standard way to chase a fresh occurrence.

What is uytenbogaardtite used for?+

Uytenbogaardtite is used in collector.

Find uytenbogaardtite on the map

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