Metatamboite is a rare secondary tellurite mineral typically occurring as fragile, platy or micaceous crystals in oxidized zones of tellurium-rich ore bodies. It is most easily identified by its distinctive yellow to brownish-orange color and association with other secondary tellurium minerals in specific localities like the Moctezuma mine.

Hardness

2-3

Mohs

Luster

Greasy to vitreous

Streak

Very pale yellow to colorless

Transparency

Transparent

mineralrare

Metatamboite

Hardness: 2-3
Luster: Greasy to vitreous
Streak: Very pale yellow to colorless
Transparency: Transparent

No image

Is this metatamboite?

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 metatamboite with a known reference. Metatamboite sits at Mohs 2-3, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: very pale yellow to colorless.
3
Read the luster
Hold the specimen under a strong light. Luster: greasy to vitreous.
4
Match the color range
Compare against the expected color range: pale yellow.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: platy crystals, tabular, micaceous aggregates.

Often confused with

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

How to tell apart: Streak differs, so Metatamboite leaves very pale yellow to colorless, Tellurite leaves white; luster reads greasy to vitreous on Metatamboite and subadamantine on Tellurite.

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Often found alongside metatamboite

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

All properties

Chemical formula: Fe₃(OH)(H₂O)₂(SO₄)(TeO₃)₃(TeO(OH)₂)(H₂O)
Mohs hardness: 2-3
Density: 4.053 g/cm³
Colors: Pale yellow
Streak: Very pale yellow to colorless
Luster: Greasy to vitreous
Transparency: Transparent
Crystal system: Monoclinic
Crystal habit: Platy crystals, tabular, micaceous aggregates
Rarity: Rare
Uses: Collector
Host rock: In the interstices of silicified epithermal hydrothermal breccias of dacitic tuff

Where rockhounds find metatamboite

Classic worldwide localities

Moctezuma mine, Sonora, Mexico
Tombstone, Arizona, USA

Field-hunting tip

Where it forms: In the interstices of silicified epithermal hydrothermal breccias of dacitic tuff. If you start seeing alunite, rodalquilarite, emmonsite in float, you are in the right ground. Typical habit: platy crystals, tabular, micaceous aggregates. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify metatamboite?+

Mohs hardness is 2-3. Luster: greasy to vitreous. The streak is very pale yellow to colorless. Common colors include pale yellow.

Where is metatamboite found?+

Notable localities include Moctezuma mine, Sonora, Mexico; Tombstone, Arizona, USA.

Is metatamboite safe to handle?+

Contains lead, which is toxic if ingested or inhaled as dust. Handle with care and wash hands thoroughly after handling.

What rocks look like metatamboite?+

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

What minerals are found with metatamboite?+

Metatamboite commonly co-occurs with Alunite, Rodalquilarite, Emmonsite, Poughite, Mackayite, Scorodite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does metatamboite form in?+

Where it forms: In the interstices of silicified epithermal hydrothermal breccias of dacitic tuff. Working float back to the host body is the standard way to chase a fresh occurrence.

What is metatamboite used for?+

Metatamboite is used in collector.

Find metatamboite on the map

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