Hydroxyferroroméite is a rare iron antimony hydroxide, typically yellow to yellow-brown. It occurs in powdery boxwork replacements after tetrahedrite in a siderite-quartz matrix (France). Associated minerals include hematite, goethite and chalcopyrite. It was first described from Correc d'en Llinassos, near Oms, Pyrénées-Orientales Department, France.

Hardness

Mohs

Luster

Earthy to vitreous

Streak

Yellow

Transparency

Translucent

mineralrareRoméite Group family

Hydroxyferroroméite

Hardness: ~3
Luster: Earthy to vitreous
Streak: Yellow
Transparency: Translucent

No image

Is this hydroxyferroroméite?

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 hydroxyferroroméite with a known reference. Hydroxyferroroméite sits at Mohs ~3, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: yellow.
3
Read the luster
Hold the specimen under a strong light. Luster: earthy to vitreous.
4
Match the color range
Compare against the expected color range: yellow, yellow-brown.
5
Look at form & habit
Crystal system: cubic. Typical habit: octahedral crystals, massive, granular.

Often confused with

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

mineral

Bindheimite

Mohs 4-4.5

How to tell apart: Bindheimite is the harder of the two (Mohs 4-4.5 vs. ~3); streak differs, so Hydroxyferroroméite leaves yellow, Bindheimite leaves white, yellowish white; luster reads earthy to vitreous on Hydroxyferroroméite and resinous, dull, earthy on Bindheimite.

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Often found alongside hydroxyferroroméite

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

All properties

Chemical formula: (Fe²⁺₁.₅☐₀.₅)Sb⁵⁺₂O₆(OH)
Mohs hardness: ~3
Density: 5.0-5.5 g/cm³
Colors: Yellow Yellow-brown
Streak: Yellow
Luster: Earthy to vitreous
Transparency: Translucent
Crystal system: Cubic
Crystal habit: Octahedral crystals, massive, granular
Rarity: Rare
Uses: Collector
Host rock: As powdery boxwork replacements after tetrahedrite in a siderite-quartz matrix (France)

Where rockhounds find hydroxyferroroméite

Classic worldwide localities

Correc d’en Llinassos, near Oms, Pyrénées-Orientales Department, France; also at the Consols Mine (ABH Consols Mine; Australian Broken Hill Consols Mine), Broken Hill, New South Wales, Australia

Field-hunting tip

Where it forms: As powdery boxwork replacements after tetrahedrite in a siderite-quartz matrix (France). If you start seeing hematite, goethite, chalcopyrite in float, you are in the right ground. Typical habit: octahedral crystals, massive, granular. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify hydroxyferroroméite?+

Mohs hardness is ~3. Luster: earthy to vitreous. The streak is yellow. Common colors include yellow, yellow-brown.

Where is hydroxyferroroméite found?+

Notable localities include Correc d’en Llinassos, near Oms, Pyrénées-Orientales Department, France; also at the Consols Mine (ABH Consols Mine; Australian Broken Hill Consols Mine), Broken Hill, New South Wales, Australia.

Is hydroxyferroroméite safe to handle?+

Hydroxyferroroméite contains antimony. Contains antimony, which is toxic if ingested or inhaled as dust. Wash hands thoroughly after handling and avoid creating dust.

What rocks look like hydroxyferroroméite?+

Hydroxyferroroméite 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 hydroxyferroroméite?+

Hydroxyferroroméite commonly co-occurs with Hematite, Goethite, Chalcopyrite, Tetrahedrite, Native antimony, Chlorargyrite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does hydroxyferroroméite form in?+

Where it forms: As powdery boxwork replacements after tetrahedrite in a siderite-quartz matrix (France). Working float back to the host body is the standard way to chase a fresh occurrence.

What is hydroxyferroroméite used for?+

Hydroxyferroroméite is used in collector.

Find hydroxyferroroméite on the map

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