Sayrite is a rare lead uranium hydroxide that forms yellow-orange to red-orange isolated prismatic crystals. It is an alteration product of uraninite in the oxidized zone of a uranium orebody. Associated minerals include uraninite, becquerelite and uranophane. It was first described from Shinkolobwe, Katanga Province, Congo (Shaba Province, Zaire).
Is this sayrite?
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 sayrite with a known reference. Sayrite sits at Mohs 2-3, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Sayrite leaves a yellow streak.
- 3Read the lusterHold the specimen under a strong light. Sayrite typically shows a vitreous to adamantine luster.
- 4Match the color rangeCompare against the expected color range: yellow-orange, red-orange.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: isolated prismatic crystals.
Often confused with
Sayrite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Kasolite is the harder of the two (Mohs 4-5 vs. 2-3); luster reads vitreous to adamantine on Sayrite and greasy on Kasolite.
How to tell apart: Streak differs, so Sayrite leaves yellow, Boltwoodite leaves white; luster reads vitreous to adamantine on Sayrite and pearly on Boltwoodite.
Often found alongside sayrite
Minerals reported to co-occur with sayrite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Pb₂(UO₂)₅O₆(OH)₂·4H₂O
- Mohs hardness
- 2-3
- Density
- 6.76 g/cm³
- Colors
- Streak
- Yellow
- Luster
- Vitreous to Adamantine
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Isolated Prismatic Crystals
- Cleavage
- {102}, Distinct
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Oxidized Zones of Uranium-bearing Hydrothermal Deposits
Where rockhounds find sayrite
Classic worldwide localities
- Shinkolobwe Mine, Democratic Republic of the Congo
Field-hunting tip
Look in oxidized zones of uranium-bearing hydrothermal deposits country, the host setting where sayrite typically forms. If you start seeing kasolite, soddyite, curite in float, you are in the right ground. Field specimens usually show a isolated prismatic crystals habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify sayrite?+
Where is sayrite found?+
Is sayrite safe to handle?+
What rocks look like sayrite?+
What minerals are found with sayrite?+
What kind of rock does sayrite form in?+
What is sayrite used for?+
Find sayrite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
