Monteponite is a rare cadmium oxide mineral that typically occurs as small, yellow to brown coatings or crusts in oxidized lead-zinc ore bodies. Due to its scarcity and association with cadmium, it is a significant find for mineral collectors focusing on rare species. It is most famous for its occurrence at the Monteponi Mine in Sardinia, Italy.
Is this monteponite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch monteponite with a known reference. Monteponite sits at Mohs 3, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: black.
- 3Read the lusterHold the specimen under a strong light. Luster: brilliant.
- 4Match the color rangeCompare against the expected color range: black.
- 5Look at form & habitCrystal system: cubic. Typical habit: crystalline.
Often confused with
Monteponite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Monteponite leaves black, Otavite leaves white; luster reads brilliant on Monteponite and vitreous to adamantine on Otavite.
How to tell apart: Streak differs, so Monteponite leaves black, Greenockite leaves yellow-orange to brick-red; luster reads brilliant on Monteponite and adamantine to resinous on Greenockite.
Often found alongside monteponite
Minerals reported to co-occur with monteponite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CdO
- Mohs hardness
- 3
- Density
- 8.1-8.2 g/cm³
- Colors
- Streak
- Black
- Luster
- Brilliant
- Transparency
- Transparent
- Crystal system
- Cubic
- Crystal habit
- Crystalline
- Cleavage
- Indistinct
- Rarity
- Rare
- Uses
- Collector
- Host rock
- As a coating over “calamine” (Genarutta mine, Sardinia, Italy); in sulfide ore (Verkhoyan’ya, Russia)
Where rockhounds find monteponite
Classic worldwide localities
- Genarutta mine, Monteponi, near Iglesias, Sardinia, Italy
- Welrath, Belgium
- Southern Verkhoyan’ya, Russia
- Hatrurim Complex, Daba-Siwaqa, Jordan
Field-hunting tip
Where it forms: As a coating over “calamine” (Genarutta mine, Sardinia, Italy); in sulfide ore (Verkhoyan’ya, Russia). If you start seeing cadmium, otavite in float, you are in the right ground. Typical habit: crystalline. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify monteponite?+
Where is monteponite found?+
Is monteponite safe to handle?+
What rocks look like monteponite?+
What minerals are found with monteponite?+
What kind of rock does monteponite form in?+
What is monteponite used for?+
Find monteponite on the map
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