Yurmarinite is a very rare sodium iron copper arsenate mineral originally discovered in the Kamchatka Peninsula of Russia. It typically appears as small, yellowish tabular crystals associated with arsenic-rich hydrothermal environments. Due to its extreme scarcity, it is considered a premier locality-specific specimen for advanced collectors.

Hardness

3.5

Mohs

Luster

Resinous

Streak

Yellow

Transparency

Translucent

mineralrarenull family

Yurmarinite

Hardness: 3.5
Luster: Resinous
Streak: Yellow
Transparency: Translucent

No image

Is this yurmarinite?

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 yurmarinite with a known reference. Yurmarinite sits at Mohs 3.5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Yurmarinite leaves a yellow streak.
3
Read the luster
Hold the specimen under a strong light. Yurmarinite typically shows a resinous luster.
4
Match the color range
Compare against the expected color range: yellow, brownish-yellow.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: small tabular crystals and crusts.

Often found alongside yurmarinite

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

All properties

Chemical formula: Na₇(Fe³⁺,Cu)₄(AsO₄)₆
Mohs hardness: 3.5
Density: 4.87 g/cm³
Colors: Yellow Brownish-yellow
Streak: Yellow
Luster: Resinous
Transparency: Translucent
Crystal system: Monoclinic
Crystal habit: Small Tabular Crystals and Crusts
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Hydrothermal Volcanic Deposits
Typical price: $50-300 per specimen depending on size and quality

Where rockhounds find yurmarinite

Classic worldwide localities

Yurmarina prospect, Russia

Field-hunting tip

Look in hydrothermal volcanic deposits country — that is the host setting where yurmarinite typically forms. If you start seeing arsenopyrite, pyrite, quartz in float, you are in the right ground. Field specimens usually show a small tabular crystals and crusts habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify yurmarinite?+

Mohs hardness is 3.5. It typically shows a resinous luster. The streak is yellow. Common colors include yellow, brownish-yellow.

Where is yurmarinite found?+

Notable localities include Yurmarina prospect, Russia.

How much is yurmarinite worth?+

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

Is yurmarinite safe to handle?+

It contains toxic constituents. Contains arsenic, which is toxic; avoid inhalation of dust, ingestion, or skin contact. Wash hands thoroughly after handling specimens. Handle with care, avoid grinding or breathing dust, and store separately.

What minerals are found with yurmarinite?+

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

What kind of rock does yurmarinite form in?+

Yurmarinite typically forms in hydrothermal volcanic deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is yurmarinite used for?+

Yurmarinite is used in collector.

Find yurmarinite on the map

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