Radekškodaite-(La) is an extremely rare member of the gadolinite group, primarily found in granitic pegmatites. It appears as small, dark, subhedral to anhedral grains associated with other rare-earth element minerals and is typically identified through analytical methods like electron microprobe analysis.

Hardness

6-7

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrareGadolinite Group family

Radekškodaite-(La)

Hardness: 6-7
Luster: Vitreous
Streak: White
Transparency: Translucent

No image

Is this radekškodaite-(la)?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

1
Test the hardness
Try to scratch radekškodaite-(la) with a known reference. Radekškodaite-(La) sits at Mohs 6-7 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Radekškodaite-(La) leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Radekškodaite-(La) typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: dark brown, black.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: anhedral grains.

Often confused with

Radekškodaite-(La) vs. its common look-alikes — and how to tell them apart in the field.

Often found alongside radekškodaite-(la)

Minerals reported to co-occur with radekškodaite-(la). Spotting these in float or country rock is a strong cue you are in the right ground.

All properties

Chemical formula: □CaLaFe³⁺Be₂Si₂O₁₀
Mohs hardness: 6-7
Density: 4.67 g/cm³
Colors: Dark Brown Black
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Monoclinic
Crystal habit: Anhedral Grains
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Pegmatite
Typical price: $50-500 depending on specimen quality and size

Where rockhounds find radekškodaite-(la)

Classic worldwide localities

Czech Republic

Field-hunting tip

Look in pegmatite country — that is the host setting where radekškodaite-(la) typically forms. If you start seeing fluorite, quartz, feldspar in float, you are in the right ground. Field specimens usually show a anhedral grains habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify radekškodaite-(la)?+

Mohs hardness is 6-7. It typically shows a vitreous luster. The streak is white. Common colors include dark brown, black.

Where is radekškodaite-(la) found?+

Notable localities include Czech Republic.

How much is radekškodaite-(la) worth?+

Typical asking prices fall in the range of $50-500 depending on specimen quality and size. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like radekškodaite-(la)?+

Radekškodaite-(La) is most often confused with Gadolinite-(Y), Datolite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with radekškodaite-(la)?+

Radekškodaite-(La) commonly co-occurs with Fluorite, Quartz, Feldspar, Allanite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does radekškodaite-(la) form in?+

Radekškodaite-(La) typically forms in pegmatite. Working float back to the host body is the standard way to chase a fresh occurrence.

What is radekškodaite-(la) used for?+

Radekškodaite-(La) is used in collector.

Find radekškodaite-(la) on the map

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