Iseite is a rare tellurite mineral discovered in the oxidized zones of the Moctezuma mine in Mexico. It typically forms thin, yellow platy crystals or crusts associated with other tellurium minerals. Its distinct adamantine luster and rarity make it a highly sought-after species for mineral collectors specializing in tellurium minerals.
Is this iseite?
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 iseite with a known reference. Iseite 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. Iseite leaves a yellow streak.
- 3Read the lusterHold the specimen under a strong light. Iseite typically shows a adamantine luster.
- 4Match the color rangeCompare against the expected color range: yellow, greenish-yellow.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: platy crystals, crusts, radial aggregates.
Often confused with
Iseite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside iseite
Minerals reported to co-occur with iseite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Fe₂(TeO₃)₃·H₂O
- Mohs hardness
- 2
- Density
- 4.9-5.0 g/cm³
- Colors
- Streak
- Yellow
- Luster
- Adamantine
- Transparency
- Translucent
- Crystal system
- Orthorhombic
- Crystal habit
- Platy Crystals, Crusts, Radial Aggregates
- Cleavage
- Perfect in One Direction
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Oxidized Tellurium-bearing Hydrothermal Deposits
- Typical price
- $100-500 for small thumbnail specimens
Where rockhounds find iseite
Classic worldwide localities
- Moctezuma mine, Sonora, Mexico
Field-hunting tip
Look in oxidized tellurium-bearing hydrothermal deposits country — that is the host setting where iseite typically forms. If you start seeing emmonsite, tellurite, paratellurite in float, you are in the right ground. Field specimens usually show a platy crystals, crusts, radial aggregates habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify iseite?+
Where is iseite found?+
How much is iseite worth?+
Is iseite safe to handle?+
What rocks look like iseite?+
What minerals are found with iseite?+
What kind of rock does iseite form in?+
What is iseite used for?+
Find iseite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
