Magnesioleydetite is a very rare uranyl carbonate mineral typically found as small, bright yellow tabular crystals. It is primarily known from the Shinkolobwe mine and requires careful handling due to its radioactive nature.
Is this magnesioleydetite?
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 magnesioleydetite with a known reference. Magnesioleydetite 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. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: pale green-yellow.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: tabular crystals.
Often confused with
Magnesioleydetite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Magnesioleydetite leaves white, Schröckingerite leaves pale yellow; luster reads vitreous on Magnesioleydetite and subvitreous, pearly on {001} on Schröckingerite.
How to tell apart: Streak differs, so Magnesioleydetite leaves white, Liebigite leaves yellow white.
Often found alongside magnesioleydetite
Minerals reported to co-occur with magnesioleydetite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Mg(UO₂)(SO₄)₂(H₂O)₇·4H₂O
- Mohs hardness
- ~2
- Density
- 2.463 g/cm³
- Colors
- Pale green-yellow
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent to translucent
- Crystal system
- Monoclinic
- Crystal habit
- Tabular crystals
- Cleavage
- Perfect on {001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A secondary phase on asphaltum found in efflorescent crusts on the surfaces of mine walls
Where rockhounds find magnesioleydetite
Classic worldwide localities
- Markey mine, Red Canyon, San Juan County, Utah, USA
Field-hunting tip
Where it forms: A secondary phase on asphaltum found in efflorescent crusts on the surfaces of mine walls. If you start seeing straβmannite, arsenuranospathite, gypsum in float, you are in the right ground. Typical habit: tabular crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify magnesioleydetite?+
Where is magnesioleydetite found?+
Is magnesioleydetite safe to handle?+
What rocks look like magnesioleydetite?+
What minerals are found with magnesioleydetite?+
What kind of rock does magnesioleydetite form in?+
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Find magnesioleydetite on the map
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