Hundholmenite-(Y) is a rare yttrium-rich member of the apatite group characterized by its yellowish-brown prismatic crystals. It is primarily found in complex granite pegmatites and is sought after by advanced collectors for its rarity and distinct chemical composition.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrareApatite Group family

Hundholmenite-(Y)

Hardness: 5
Luster: Vitreous
Streak: White
Transparency: Translucent

No image

Is this hundholmenite-(y)?

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 hundholmenite-(y) with a known reference. Hundholmenite-(Y) sits at Mohs 5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Hundholmenite-(Y) leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Hundholmenite-(Y) typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: yellow, brown, brownish-yellow.
5
Look at form & habit
Crystal system: hexagonal. Typical habit: prismatic crystals.

Often confused with

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

Often found alongside hundholmenite-(y)

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

All properties

Chemical formula: (Y,REE,Ca,Na)₅(Si,P,B)₃O₁₂(OH,F)
Mohs hardness: 5
Density: 4.15 g/cm³
Colors: Yellow Brown Brownish-yellow
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Hexagonal
Crystal habit: Prismatic Crystals
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Granite Pegmatites
Typical price: $50-300 per specimen

Where rockhounds find hundholmenite-(y)

Classic worldwide localities

Hundholmen, Tysfjord, Norway

Field-hunting tip

Look in granite pegmatites country — that is the host setting where hundholmenite-(y) typically forms. If you start seeing quartz, feldspar, biotite in float, you are in the right ground. Field specimens usually show a prismatic crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify hundholmenite-(y)?+

Mohs hardness is 5. It typically shows a vitreous luster. The streak is white. Common colors include yellow, brown, brownish-yellow.

Where is hundholmenite-(y) found?+

Notable localities include Hundholmen, Tysfjord, Norway.

How much is hundholmenite-(y) worth?+

Typical asking prices fall in the range of $50-300 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

Is hundholmenite-(y) safe to handle?+

This mineral is radioactive. Contains rare earth elements and thorium, handle with care and wash hands after contact. Store away from living spaces to minimize radon exposure. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like hundholmenite-(y)?+

Hundholmenite-(Y) is most often confused with Apatite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with hundholmenite-(y)?+

Hundholmenite-(Y) commonly co-occurs with Quartz, Feldspar, Biotite, Gadolinite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does hundholmenite-(y) form in?+

Hundholmenite-(Y) typically forms in granite pegmatites. Working float back to the host body is the standard way to chase a fresh occurrence.

What is hundholmenite-(y) used for?+

Hundholmenite-(Y) is used in collector.

Find hundholmenite-(y) on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.