Kapitsaite-(Y) is an extremely rare silicate mineral found in the unique alkaline pegmatites of the Dara-i-Pioz massif in Tajikistan. It typically occurs as small yellowish-pale pink tabular crystals associated with other rare REE-bearing silicates and borosilicates.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrareGatelite Group family

Kapitsaite-(Y)

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

No image

Is this kapitsaite-(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 kapitsaite-(y) with a known reference. Kapitsaite-(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. Kapitsaite-(Y) leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Kapitsaite-(Y) typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: pale pink.
5
Look at form & habit
Crystal system: triclinic. Typical habit: tabular crystals, subhedral grains.

Often confused with

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

mineral

Allanite

Mohs 5.5-6

How to tell apart: Streak differs, so Kapitsaite-(Y) leaves white, Allanite leaves gray; luster reads vitreous on Kapitsaite-(Y) and submetallic on Allanite.

Compare →

Often found alongside kapitsaite-(y)

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

All properties

Chemical formula: Ba₄Y₂Si₈B₄O₂₈F
Mohs hardness: 5
Density: 3.74 g/cm³
Colors: Pale Pink
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Triclinic
Crystal habit: Tabular Crystals, Subhedral Grains
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Alkaline Pegmatites

Where rockhounds find kapitsaite-(y)

Classic worldwide localities

Dara-i-Pioz Glacier, Tajikistan

Field-hunting tip

Look in alkaline pegmatites country, the host setting where kapitsaite-(y) typically forms. If you start seeing quartz, microcline, aegirine in float, you are in the right ground. Field specimens usually show a tabular crystals, subhedral grains habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify kapitsaite-(y)?+

Mohs hardness is 5. It typically shows a vitreous luster. The streak is white. Common colors include pale pink.

Where is kapitsaite-(y) found?+

Notable localities include Dara-i-Pioz Glacier, Tajikistan.

What rocks look like kapitsaite-(y)?+

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

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

Kapitsaite-(Y) commonly co-occurs with Quartz, Microcline, Aegirine, Pectolite, Hyalotekite. Spotting any of these in float or country rock is a useful trip signal.

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

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

What is kapitsaite-(y) used for?+

Kapitsaite-(Y) is used in collector.

Find kapitsaite-(y) on the map

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