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 — that is 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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