Goldichite is a rare secondary sulfate mineral typically found as an oxidation product of iron sulfide minerals. It often occurs as thin, white to pale yellow tabular crystals or powdery coatings in arid mining districts. Because it is water-soluble, it should be kept in a dry environment to prevent degradation.
Is this goldichite?
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 goldichite with a known reference. Goldichite sits at Mohs ~2.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: light yellow green.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: tabular crystals, granular crusts.
Often confused with
Goldichite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside goldichite
Minerals reported to co-occur with goldichite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- KFe(SO₄)₂·4H₂O
- Mohs hardness
- ~2.5
- Density
- 2.43 g/cm³
- Colors
- Light yellow green
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Tabular crystals, granular crusts
- Cleavage
- On {100}, perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Cementing fragments in slope debris from an oxidizing pyritiferous Colorado Plateau-type uranium deposit (Dexter No. 7 mine, Utah, USA)
Where rockhounds find goldichite
Classic worldwide localities
- Dexter No. 7 mine, Calf Mesa, San Rafael district, Emery Co., Utah, USA
- Santa Bárbara sulfur mine, El Palmar district, Jujuy Province, Argentina
- Lanjarón mineral springs, Granada Province, Spain
- Island of Saba, Netherland Antilles
Field-hunting tip
Where it forms: Cementing fragments in slope debris from an oxidizing pyritiferous Colorado Plateau-type uranium deposit (Dexter No. 7 mine, Utah, USA). If you start seeing alunogen, coquimbite, copiapite in float, you are in the right ground. Typical habit: tabular crystals, granular crusts. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify goldichite?+
Where is goldichite found?+
What rocks look like goldichite?+
What minerals are found with goldichite?+
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What is goldichite used for?+
Find goldichite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
