Rosiaite is a very rare lead-antimony oxide mineral originally discovered in the gold-mining district of Rosia Montana, Romania. It typically forms small, distinct yellow crystals associated with other secondary lead minerals and gold-bearing ores.

Hardness

3-4

Mohs

Luster

Resinous

Streak

Yellowish-white

Transparency

Translucent

mineralrarePyrochlore Supergroup family

Rosiaite

Hardness: 3-4
Luster: Resinous
Streak: Yellowish-white
Transparency: Translucent

Is this rosiaite?

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 rosiaite with a known reference. Rosiaite sits at Mohs 3-4 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Rosiaite leaves a yellowish-white streak.
3
Read the luster
Hold the specimen under a strong light. Rosiaite typically shows a resinous luster.
4
Match the color range
Compare against the expected color range: yellow, yellow-brown.
5
Look at form & habit
Crystal system: trigonal. Typical habit: tabular to rhombohedral crystals.

Often confused with

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

mineral

Bindheimite

Mohs 4-4.5

How to tell apart: Streak differs — Rosiaite leaves yellowish-white, Bindheimite leaves yellow; luster reads resinous on Rosiaite and earthy on Bindheimite.

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Often found alongside rosiaite

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

All properties

Chemical formula: PbSb₂O₆
Mohs hardness: 3-4
Density: 4.95 g/cm³
Colors: Yellow Yellow-brown
Streak: Yellowish-white
Luster: Resinous
Transparency: Translucent
Crystal system: Trigonal
Crystal habit: Tabular to Rhombohedral Crystals
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Hydrothermal Epithermal Gold-silver Deposits
Typical price: $50-300 per specimen

Where rockhounds find rosiaite

Classic worldwide localities

Rosia Montana, Romania

Field-hunting tip

Look in hydrothermal epithermal gold-silver deposits country — that is the host setting where rosiaite typically forms. If you start seeing quartz, pyrite, galena in float, you are in the right ground. Field specimens usually show a tabular to rhombohedral crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify rosiaite?+

Mohs hardness is 3-4. It typically shows a resinous luster. The streak is yellowish-white. Common colors include yellow, yellow-brown.

Where is rosiaite found?+

Notable localities include Rosia Montana, Romania.

How much is rosiaite worth?+

Typical asking prices fall in the range of $50-300 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

Is rosiaite safe to handle?+

It contains toxic constituents. Contains lead and antimony; wash hands thoroughly after handling and avoid inhaling dust. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like rosiaite?+

Rosiaite is most often confused with Bindheimite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with rosiaite?+

Rosiaite commonly co-occurs with Quartz, Pyrite, Galena, Sphalerite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does rosiaite form in?+

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

What is rosiaite used for?+

Rosiaite is used in collector.

Find rosiaite on the map

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