Clinoferrosilite is a rare monoclinic pyroxene found primarily in high-grade metamorphic iron formations. It is difficult to distinguish from orthopyroxene without laboratory analysis and is most prized by advanced mineral collectors specializing in silicate species.

Hardness

5-6

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrarePyroxene Group family

Clinoferrosilite

Hardness: 5-6
Luster: Vitreous
Streak: White
Transparency: Translucent

Is this clinoferrosilite?

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 clinoferrosilite with a known reference. Clinoferrosilite sits at Mohs 5-6, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Clinoferrosilite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Clinoferrosilite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: brown, greenish-brown, black.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: prismatic crystals, massive.

Often confused with

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

mineral

Hedenbergite

Mohs 5.5-6

How to tell apart: Streak differs, so Clinoferrosilite leaves white, Hedenbergite leaves white to pale green; luster reads vitreous on Clinoferrosilite and vitreous to resinous on Hedenbergite.

Often found alongside clinoferrosilite

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

All properties

Chemical formula: Fe₂Si₂O₆
Mohs hardness: 5-6
Density: 3.8-3.9 g/cm³
Colors: Brown Greenish-brown Black
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Monoclinic
Crystal habit: Prismatic Crystals, Massive
Cleavage: Good in 2 Directions
Rarity: Rare
Uses: Collector
Host rock: Metamorphic Rocks, Iron Formations
Typical price: $20-200 thumbnail

Where rockhounds find clinoferrosilite

Classic worldwide localities

Japan
USA
Greenland
Germany

Field-hunting tip

Look in metamorphic rocks, iron formations country, the host setting where clinoferrosilite typically forms. If you start seeing quartz, fayalite, magnetite in float, you are in the right ground. Field specimens usually show a prismatic crystals, massive habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify clinoferrosilite?+

Mohs hardness is 5-6. It typically shows a vitreous luster. The streak is white. Common colors include brown, greenish-brown, black.

Where is clinoferrosilite found?+

Notable localities include Japan; USA; Greenland; Germany.

How much is clinoferrosilite worth?+

Typical asking prices fall in the range of $20-200 thumbnail. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like clinoferrosilite?+

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

What minerals are found with clinoferrosilite?+

Clinoferrosilite commonly co-occurs with Quartz, Fayalite, Magnetite, Grunerite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does clinoferrosilite form in?+

Clinoferrosilite typically forms in metamorphic rocks, iron formations. Working float back to the host body is the standard way to chase a fresh occurrence.

What is clinoferrosilite used for?+

Clinoferrosilite is used in collector.

Find clinoferrosilite on the map

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