Hydroxylclinohumite is a rare member of the Humite group found primarily in contact metamorphic zones of carbonate rocks. Collectors prize it for its vibrant yellow to brownish-orange hues and occasional gem-grade clarity, which is often mistaken for other humite minerals without rigorous chemical testing.

Hardness

6.5

Mohs

Luster

Vitreous to dull

Streak

White

Transparency

Transparent to translucent

mineralrareHumite Group family

Hydroxylclinohumite

Hardness: 6.5
Luster: Vitreous to dull
Streak: White
Transparency: Transparent to translucent

No image

Is this hydroxylclinohumite?

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 hydroxylclinohumite with a known reference. Hydroxylclinohumite sits at Mohs 6.5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: white.
3
Read the luster
Hold the specimen under a strong light. Luster: vitreous to dull.
4
Match the color range
Compare against the expected color range: yellow orange, pale yellow.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: granular.

Often confused with

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

mineral

Chondrodite

Mohs 6-6.5

How to tell apart: Streak differs, so Hydroxylclinohumite leaves white, Chondrodite leaves gray.

Often found alongside hydroxylclinohumite

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

Calcite
mineral · Mohs 3

All properties

Chemical formula: Mg₉(SiO₄)₄(OH)₂
Mohs hardness: 6.5
Density: 3.13 g/cm³
Colors: Yellow orange Pale yellow
Streak: White
Luster: Vitreous to dull
Transparency: Transparent to translucent
Crystal system: Monoclinic
Crystal habit: Granular
Cleavage: None
Rarity: Rare
Uses: Collector, Lapidary
Host rock: In Mg-skarn (calciphyric) rims on dolomitic marble xenoliths in gabbroic rocks and associated Fe-Ti ore

Where rockhounds find hydroxylclinohumite

Classic worldwide localities

Zelentsovskaya mine, Mt. Protopop, Magnitka, near Zlatoust, southern Urals, Russia

Field-hunting tip

Where it forms: In Mg-skarn (calciphyric) rims on dolomitic marble xenoliths in gabbroic rocks and associated Fe-Ti ore. If you start seeing ferroan spinel, calcite in float, you are in the right ground. Typical habit: granular. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify hydroxylclinohumite?+

Mohs hardness is 6.5. Luster: vitreous to dull. The streak is white. Common colors include yellow orange, pale yellow.

Where is hydroxylclinohumite found?+

Notable localities include Zelentsovskaya mine, Mt. Protopop, Magnitka, near Zlatoust, southern Urals, Russia.

What rocks look like hydroxylclinohumite?+

Hydroxylclinohumite is most often confused with Chondrodite, Humite, Clinohumite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with hydroxylclinohumite?+

Hydroxylclinohumite commonly co-occurs with Ferroan spinel, Calcite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does hydroxylclinohumite form in?+

Where it forms: In Mg-skarn (calciphyric) rims on dolomitic marble xenoliths in gabbroic rocks and associated Fe-Ti ore. Working float back to the host body is the standard way to chase a fresh occurrence.

What is hydroxylclinohumite used for?+

Hydroxylclinohumite is used in collector, lapidary.

Find hydroxylclinohumite on the map

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