Ardennite-(V) is a rare manganese-vanadium sorosilicate mineral that typically forms as prismatic to acicular crystals within manganese deposits. It is most recognized for its distinct yellow-brown color and its association with other manganese-rich silicate minerals in metamorphosed sedimentary environments.

Hardness

6-7

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrareArdennite Group family

Ardennite-(V)

Hardness: 6-7
Luster: Vitreous
Streak: White
Transparency: Transparent

Is this ardennite-(v)?

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 ardennite-(v) with a known reference. Ardennite-(V) sits at Mohs 6-7, 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.
4
Match the color range
Compare against the expected color range: yellow.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: acicular, tabular.

Often confused with

Ardennite-(V) vs. its common look-alikes, and how to tell them apart in the field.

mineral

Epidote

Mohs 6-7

How to tell apart: Streak differs, so Ardennite-(V) leaves white, Epidote leaves grayish white.

How to tell apart: Streak differs, so Ardennite-(V) leaves white, Clinozoisite leaves grayish white.

Compare →

Often found alongside ardennite-(v)

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

All properties

Chemical formula: Mn₄(AlMg)Al₄(Si₅V)O₂₂(OH)₆
Mohs hardness: 6-7
Density: 3.55 g/cm³
Colors: Yellow
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Orthorhombic
Crystal habit: Acicular, tabular
Cleavage: None observed
Rarity: Rare
Uses: Collector
Host rock: In a quartz veinlet in piemontite-bearing mica schist

Where rockhounds find ardennite-(v)

Classic worldwide localities

Sparone, Locana Valley (TO), Piedmont, Italy

Field-hunting tip

Where it forms: In a quartz veinlet in piemontite-bearing mica schist. If you start seeing quartz, piemontite, hematite in float, you are in the right ground. Typical habit: acicular, tabular. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify ardennite-(v)?+

Mohs hardness is 6-7. Luster: vitreous. The streak is white. Common colors include yellow.

Where is ardennite-(v) found?+

Notable localities include Sparone, Locana Valley (TO), Piedmont, Italy.

Is ardennite-(v) safe to handle?+

Ardennite-(V) contains vanadium. Contains arsenic, which is toxic; wash hands thoroughly after handling and avoid inhaling dust during preparation or cleaning.

What rocks look like ardennite-(v)?+

Ardennite-(V) is most often confused with Epidote, Clinozoisite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with ardennite-(v)?+

Ardennite-(V) commonly co-occurs with Quartz, Piemontite, Hematite, Muscovite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does ardennite-(v) form in?+

Where it forms: In a quartz veinlet in piemontite-bearing mica schist. Working float back to the host body is the standard way to chase a fresh occurrence.

What is ardennite-(v) used for?+

Ardennite-(V) is used in collector.

Find ardennite-(v) on the map

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