Molinelloite is a rare copper vanadium hydroxide. It was approved as a distinct mineral species in 2016. It was first described from Molinello mine, Ne, Val Graveglia, Genova district, Liguria, Italy.

Hardness

Mohs

Luster

Vitreous

Streak

Pale Blue

Transparency

Transparent

mineralrare

Molinelloite

Hardness: 3
Luster: Vitreous
Streak: Pale Blue
Transparency: Transparent

Is this molinelloite?

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 molinelloite with a known reference. Molinelloite 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. Molinelloite leaves a pale blue streak.
3
Read the luster
Hold the specimen under a strong light. Molinelloite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: blue, deep blue.
5
Look at form & habit
Crystal system: triclinic. Typical habit: acicular or prismatic crystals, commonly in radial sprays.

Often confused with

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

mineral

Chrysocolla

Mohs 2-4

How to tell apart: Streak differs, so Molinelloite leaves pale blue, Chrysocolla leaves white.

How to tell apart: Streak differs, so Molinelloite leaves pale blue, Shattuckite leaves blue; luster reads vitreous on Molinelloite and silky on Shattuckite.

Compare →

Often found alongside molinelloite

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

All properties

Chemical formula: Cu(H₂O)(OH)V⁴⁺O(V⁵⁺O₄)
Mohs hardness: 3
Density: 3.51 g/cm³
Colors: Blue Deep Blue
Streak: Pale Blue
Luster: Vitreous
Transparency: Transparent
Crystal system: Triclinic
Crystal habit: Acicular or Prismatic Crystals, Commonly in Radial Sprays
Cleavage: Good in One Direction
Rarity: Rare
Uses: Collector
Host rock: Manganese-rich Cherts and Metamorphic Rocks

Where rockhounds find molinelloite

Classic worldwide localities

Molinello Mine, Italy
Gambatesa Mine, Italy

Field-hunting tip

Look in manganese-rich cherts and metamorphic rocks country, the host setting where molinelloite typically forms. If you start seeing braunite, quartz, calcite in float, you are in the right ground. Field specimens usually show a acicular or prismatic crystals, commonly in radial sprays habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify molinelloite?+

Mohs hardness is 3. It typically shows a vitreous luster. The streak is pale blue. Common colors include blue, deep blue.

Where is molinelloite found?+

Notable localities include Molinello Mine, Italy; Gambatesa Mine, Italy.

Is molinelloite safe to handle?+

It contains toxic constituents. Contains copper and vanadium, which are toxic if ingested or inhaled as dust. Wash hands thoroughly after handling and avoid creating dust. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like molinelloite?+

Molinelloite is most often confused with Chrysocolla, Shattuckite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with molinelloite?+

Molinelloite commonly co-occurs with Braunite, Quartz, Calcite, Rhodochrosite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does molinelloite form in?+

Molinelloite typically forms in manganese-rich cherts and metamorphic rocks. Working float back to the host body is the standard way to chase a fresh occurrence.

What is molinelloite used for?+

Molinelloite is used in collector.

Find molinelloite on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.