Tlalocite is a very rare copper-zinc tellurite mineral discovered in the Moctezuma mine. It typically appears as bright azure-blue acicular crystals or thin crusts, often associated with other rare tellurium species in oxidized ore zones.
Is this tlalocite?
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 tlalocite with a known reference. Tlalocite sits at Mohs 2 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Tlalocite leaves a pale blue streak.
- 3Read the lusterHold the specimen under a strong light. Tlalocite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: azure, bright blue.
- 5Look at form & habitCrystal system: hexagonal. Typical habit: acicular crystals, radiating sprays, crusts.
Often confused with
Tlalocite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Quetzalcoatlite is the harder of the two (Mohs 3 vs. 2); streak differs — Tlalocite leaves pale blue, Quetzalcoatlite leaves yellow.
How to tell apart: Denningite is the harder of the two (Mohs 3 vs. 2); streak differs — Tlalocite leaves pale blue, Denningite leaves white.
Often found alongside tlalocite
Minerals reported to co-occur with tlalocite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Cu₁₀Zn₆(TeO₃)(TeO₄)₂Cl(OH)₂₅·27H₂O
- Mohs hardness
- 2
- Density
- 5.3 g/cm³
- Colors
- Streak
- Pale Blue
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Hexagonal
- Crystal habit
- Acicular Crystals, Radiating Sprays, Crusts
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Oxidized Tellurium-bearing Hydrothermal Deposits
- Typical price
- $100-500+ for micro-specimens
Where rockhounds find tlalocite
Classic worldwide localities
- Moctezuma mine, Sonora, Mexico
Field-hunting tip
Look in oxidized tellurium-bearing hydrothermal deposits country — that is the host setting where tlalocite typically forms. If you start seeing tellurite, paratellurite, rodalquilarite in float, you are in the right ground. Field specimens usually show a acicular crystals, radiating sprays, crusts habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify tlalocite?+
Where is tlalocite found?+
How much is tlalocite worth?+
Is tlalocite safe to handle?+
What rocks look like tlalocite?+
What minerals are found with tlalocite?+
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Find tlalocite on the map
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