Shuiskite-(Cr) is a rare chromium-rich member of the pumpellyite group, typically occurring as dark green, radiating fibrous aggregates. It is most famously found in chromite-bearing metamorphic deposits where it forms as an alteration product of primary chromium minerals.

Hardness

Mohs

Luster

Vitreous

Streak

Pale Green

Transparency

Translucent

mineralrarePumpellyite Group family

Shuiskite-(Cr)

Hardness: 6
Luster: Vitreous
Streak: Pale Green
Transparency: Translucent

Is this shuiskite-(cr)?

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 shuiskite-(cr) with a known reference. Shuiskite-(Cr) sits at Mohs 6 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Shuiskite-(Cr) leaves a pale green streak.
3
Read the luster
Hold the specimen under a strong light. Shuiskite-(Cr) typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: dark green, blackish green.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: fibrous aggregates, radiating laths.

Often confused with

Shuiskite-(Cr) vs. its common look-alikes — and how to tell them apart in the field.

mineral

Clinochlore

Mohs 2-2.5

How to tell apart: Shuiskite-(Cr) is noticeably harder (Mohs 6 vs. 2-2.5); streak differs — Shuiskite-(Cr) leaves pale green, Clinochlore leaves white; luster reads vitreous on Shuiskite-(Cr) and pearly on Clinochlore.

How to tell apart: Streak differs — Shuiskite-(Cr) leaves pale green, Epidote leaves white.

Compare →

Often found alongside shuiskite-(cr)

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

All properties

Chemical formula: Ca₂MgCr₂(SiO₄)(Si₂O₇)(OH)₂·H₂O
Mohs hardness: 6
Density: 3.35 g/cm³
Colors: Dark Green Blackish Green
Streak: Pale Green
Luster: Vitreous
Transparency: Translucent
Crystal system: Monoclinic
Crystal habit: Fibrous Aggregates, Radiating Laths
Cleavage: Good
Rarity: Rare
Uses: Collector
Host rock: Chromite-bearing Metamorphic Rocks
Typical price: $50-300 per specimen

Where rockhounds find shuiskite-(cr)

Classic worldwide localities

Shuiskoe deposit, Karelia, Russia
Southeastern Ural Mountains

Field-hunting tip

Look in chromite-bearing metamorphic rocks country — that is the host setting where shuiskite-(cr) typically forms. If you start seeing chromite, uvarovite, chlorite in float, you are in the right ground. Field specimens usually show a fibrous aggregates, radiating laths habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify shuiskite-(cr)?+

Mohs hardness is 6. It typically shows a vitreous luster. The streak is pale green. Common colors include dark green, blackish green.

Where is shuiskite-(cr) found?+

Notable localities include Shuiskoe deposit, Karelia, Russia; Southeastern Ural Mountains.

How much is shuiskite-(cr) 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.

What rocks look like shuiskite-(cr)?+

Shuiskite-(Cr) is most often confused with Clinochlore, Epidote. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with shuiskite-(cr)?+

Shuiskite-(Cr) commonly co-occurs with Chromite, Uvarovite, Chlorite, Quartz. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does shuiskite-(cr) form in?+

Shuiskite-(Cr) typically forms in chromite-bearing metamorphic rocks. Working float back to the host body is the standard way to chase a fresh occurrence.

What is shuiskite-(cr) used for?+

Shuiskite-(Cr) is used in collector.

Find shuiskite-(cr) on the map

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