Yttrocolumbite-(Y) is a rare yttrium-rich niobium-tantalum oxide found primarily in complex granitic pegmatites. It typically appears as dark, resinous, massive material and is often radioactive due to the presence of uranium within its crystal structure.

Hardness

Mohs

Luster

Vitreous

Streak

Brown

Transparency

Translucent

mineralrareColumbite Group family

Yttrocolumbite-(Y)

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

Is this yttrocolumbite-(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 yttrocolumbite-(y) with a known reference. Yttrocolumbite-(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. Streak: brown.
3
Read the luster
Hold the specimen under a strong light. Luster: vitreous.
4
Match the color range
Compare against the expected color range: black.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: massive, tabular crystals, or crusts.

Often confused with

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

mineral

Columbite

Mohs 6

How to tell apart: Columbite is the harder of the two (Mohs 6 vs. 5); streak differs, so Yttrocolumbite-(Y) leaves brown, Columbite leaves blackish brown; luster reads vitreous on Yttrocolumbite-(Y) and submetallic on Columbite.

Compare →

Often found alongside yttrocolumbite-(y)

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

All properties

Chemical formula: (Y,U,Fe)₂(Nb,Ta)₂O₆
Mohs hardness: 5
Density: 5.49 g/cm³
Colors: Black
Streak: Brown
Luster: Vitreous
Transparency: Translucent
Crystal system: Orthorhombic
Crystal habit: Massive, tabular crystals, or crusts
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: A rare accessory mineral in granite pegmatites

Where rockhounds find yttrocolumbite-(y)

Classic worldwide localities

Mozambique (type locality)

Field-hunting tip

Where it forms: A rare accessory mineral in granite pegmatites. If you start seeing feldspar, quartz, mica in float, you are in the right ground. Typical habit: massive, tabular crystals, or crusts. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify yttrocolumbite-(y)?+

Mohs hardness is 5. Luster: vitreous. The streak is brown. Common colors include black.

Where is yttrocolumbite-(y) found?+

Notable localities include Mozambique (type locality).

Is yttrocolumbite-(y) safe to handle?+

Yttrocolumbite-(Y) contains uranium or thorium and calls for real care. Contains uranium and yttrium; emits low-level radiation and should be stored properly in a sealed container, handled with minimal skin contact, and not stored in living or sleeping areas.

What rocks look like yttrocolumbite-(y)?+

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

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

Yttrocolumbite-(Y) commonly co-occurs with Feldspar, Quartz, Mica, Monazite, Zircon. Spotting any of these in float or country rock is a useful trip signal.

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

Where it forms: A rare accessory mineral in granite pegmatites. Working float back to the host body is the standard way to chase a fresh occurrence.

What is yttrocolumbite-(y) used for?+

Yttrocolumbite-(Y) is used in collector.

Find yttrocolumbite-(y) on the map

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