Gaildunningite is an extremely rare tellurate mineral known primarily from the Centennial Eureka mine in Utah. It typically occurs as small, yellow, platy crystals or thin crusts associated with other secondary telluride species in oxidized ore zones.
Is this gaildunningite?
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 gaildunningite with a known reference. Gaildunningite 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. Gaildunningite leaves a yellow streak.
- 3Read the lusterHold the specimen under a strong light. Gaildunningite typically shows a adamantine luster.
- 4Match the color rangeCompare against the expected color range: yellow, brownish-yellow.
- 5Look at form & habitCrystal system: tetragonal. Typical habit: platy crystals, crusts.
Often confused with
Gaildunningite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Streak differs — Gaildunningite leaves yellow, Tellurite leaves white.
How to tell apart: Emmonsite is the harder of the two (Mohs 5 vs. 2); streak differs — Gaildunningite leaves yellow, Emmonsite leaves pale yellow; luster reads adamantine on Gaildunningite and vitreous on Emmonsite.
Often found alongside gaildunningite
Minerals reported to co-occur with gaildunningite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Pb₂ZnTeO₆
- Mohs hardness
- 2
- Density
- 4.15 g/cm³
- Colors
- Streak
- Yellow
- Luster
- Adamantine
- Transparency
- Translucent
- Crystal system
- Tetragonal
- Crystal habit
- Platy Crystals, Crusts
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Oxidized Hydrothermal Telluride Deposits
- Typical price
- $50-300 per specimen
Where rockhounds find gaildunningite
Classic worldwide localities
- Centennial Eureka mine, Utah, USA
Field-hunting tip
Look in oxidized hydrothermal telluride deposits country — that is the host setting where gaildunningite typically forms. If you start seeing tellurite, emmonsite, quetzalcoatlite in float, you are in the right ground. Field specimens usually show a platy crystals, crusts habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify gaildunningite?+
Where is gaildunningite found?+
How much is gaildunningite worth?+
Is gaildunningite safe to handle?+
What rocks look like gaildunningite?+
What minerals are found with gaildunningite?+
What kind of rock does gaildunningite form in?+
What is gaildunningite used for?+
Find gaildunningite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
