Samarskite-(Yb) is a rare radioactive yttrium-niobium mineral typically found in complex granite pegmatites. It is often metamict due to internal radiation damage, meaning its internal crystal structure has been destroyed over time, resulting in a glass-like appearance.
Is this samarskite-(yb)?
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 samarskite-(yb) with a known reference. Samarskite-(Yb) sits at Mohs 5-6, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Samarskite-(Yb) leaves a dark brown streak.
- 3Read the lusterHold the specimen under a strong light. Samarskite-(Yb) typically shows a submetallic luster.
- 4Match the color rangeCompare against the expected color range: black, brownish-black.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: prismatic, massive, or embedded grains.
Often confused with
Samarskite-(Yb) vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Samarskite-(Yb) leaves dark brown, Columbium Ore leaves dark red to black.
How to tell apart: Streak differs, so Samarskite-(Yb) leaves dark brown, Tantalite leaves black to reddish-brown; luster reads submetallic on Samarskite-(Yb) and submetallic to resinous on Tantalite.
How to tell apart: Streak differs, so Samarskite-(Yb) leaves dark brown, Euxenite-(Y) leaves yellowish-brown.
Often found alongside samarskite-(yb)
Minerals reported to co-occur with samarskite-(yb). Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- YbFe³⁺NbO₅
- Mohs hardness
- 5-6
- Density
- 5.6-6.2 g/cm³
- Colors
- Streak
- Dark Brown
- Luster
- Submetallic
- Transparency
- Opaque
- Crystal system
- Orthorhombic
- Crystal habit
- Prismatic, Massive, Or Embedded Grains
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Granite Pegmatites
Where rockhounds find samarskite-(yb)
Classic worldwide localities
- Norway
- Russia
- USA (Colorado)
- Madagascar
Field-hunting tip
Look in granite pegmatites country, the host setting where samarskite-(yb) typically forms. If you start seeing zircon, monazite, beryl in float, you are in the right ground. Field specimens usually show a prismatic, massive, or embedded grains habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify samarskite-(yb)?+
Where is samarskite-(yb) found?+
Is samarskite-(yb) safe to handle?+
What rocks look like samarskite-(yb)?+
What minerals are found with samarskite-(yb)?+
What kind of rock does samarskite-(yb) form in?+
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Find samarskite-(yb) on the map
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