Denningite is a rare tellurite mineral discovered in the Moctezuma Mine in Mexico. It typically forms thin, transparent, tabular crystals and is highly prized by collectors for its unique association with other rare tellurium minerals.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Denningite

Hardness: 3
Luster: Vitreous
Streak: White
Transparency: Transparent

Is this denningite?

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 denningite with a known reference. Denningite 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. Denningite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Denningite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: colorless, pale green.
5
Look at form & habit
Crystal system: tetragonal. Typical habit: tabular crystals.

Often confused with

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

mineral

Quetzalcoatlite

Mohs 3

How to tell apart: Streak differs — Denningite leaves white, Quetzalcoatlite leaves yellow.

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Often found alongside denningite

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

All properties

Chemical formula: (Mn,Zn,Mg)Te₂O₅
Mohs hardness: 3
Density: 4.56 g/cm³
Colors: Colorless Pale Green
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Tetragonal
Crystal habit: Tabular Crystals
Cleavage: Perfect
Rarity: Rare
Uses: Collector
Host rock: Tellurium-rich Hydrothermal Veins
Typical price: $50-300 per specimen

Where rockhounds find denningite

Classic worldwide localities

Moctezuma Mine, Sonora, Mexico

Field-hunting tip

Look in tellurium-rich hydrothermal veins country — that is the host setting where denningite typically forms. If you start seeing tellurite, paratellurite, quetzalcoatlite in float, you are in the right ground. Field specimens usually show a tabular crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify denningite?+

Mohs hardness is 3. It typically shows a vitreous luster. The streak is white. Common colors include colorless, pale green.

Where is denningite found?+

Notable localities include Moctezuma Mine, Sonora, Mexico.

How much is denningite worth?+

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

Is denningite safe to handle?+

It contains toxic constituents. Contains tellurium; avoid inhaling dust or ingesting particles. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like denningite?+

Denningite is most often confused with Quetzalcoatlite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with denningite?+

Denningite commonly co-occurs with Tellurite, Paratellurite, Quetzalcoatlite, Emmonsite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does denningite form in?+

Denningite typically forms in tellurium-rich hydrothermal veins. Working float back to the host body is the standard way to chase a fresh occurrence.

What is denningite used for?+

Denningite is used in collector.

Find denningite on the map

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