Hydroxycalcioroméite is a rare member of the pyrochlore supergroup, typically forming distinct octahedral crystals in manganese-rich metamorphic deposits. It is often found in association with other rare manganese minerals and is prized by advanced micromount collectors for its aesthetic crystal form.

Hardness

5-5.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrareRoméite Group family

Hydroxycalcioroméite

Hardness: 5-5.5
Luster: Vitreous
Streak: White
Transparency: Translucent

No image

Is this hydroxycalcioroméite?

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 hydroxycalcioroméite with a known reference. Hydroxycalcioroméite sits at Mohs 5-5.5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Hydroxycalcioroméite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Hydroxycalcioroméite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: yellow, yellow-brown, brown, colorless.
5
Look at form & habit
Crystal system: cubic. Typical habit: octahedral crystals, massive.

Often found alongside hydroxycalcioroméite

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

All properties

Chemical formula: Ca₂Sb₂O₆(OH)
Mohs hardness: 5-5.5
Density: 4.8-5.2 g/cm³
Colors: Yellow Yellow-brown Brown Colorless
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Cubic
Crystal habit: Octahedral Crystals, Massive
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Manganese Ore Deposits, Metamorphic Rocks
Typical price: $50-300 per thumbnail or small specimen

Where rockhounds find hydroxycalcioroméite

Classic worldwide localities

St. Marcel-Praborna, Italy
Långban, Sweden
Franklin, New Jersey, USA

Field-hunting tip

Look in manganese ore deposits, metamorphic rocks country, the host setting where hydroxycalcioroméite typically forms. If you start seeing braunite, hausmannite, calcite in float, you are in the right ground. Field specimens usually show a octahedral crystals, massive habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify hydroxycalcioroméite?+

Mohs hardness is 5-5.5. It typically shows a vitreous luster. The streak is white. Common colors include yellow, yellow-brown, brown, colorless.

Where is hydroxycalcioroméite found?+

Notable localities include St. Marcel-Praborna, Italy; Långban, Sweden; Franklin, New Jersey, USA.

How much is hydroxycalcioroméite worth?+

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

Is hydroxycalcioroméite safe to handle?+

It contains toxic constituents. Contains antimony, which is toxic if ingested or inhaled as dust; wash hands thoroughly after handling specimens. Handle with care, avoid grinding or breathing dust, and store separately.

What minerals are found with hydroxycalcioroméite?+

Hydroxycalcioroméite commonly co-occurs with braunite, hausmannite, calcite, diopside. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does hydroxycalcioroméite form in?+

Hydroxycalcioroméite typically forms in manganese ore deposits, metamorphic rocks. Working float back to the host body is the standard way to chase a fresh occurrence.

What is hydroxycalcioroméite used for?+

Hydroxycalcioroméite is used in collector.

Find hydroxycalcioroméite on the map

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