Ashcroftine-(Y) is a rare potassium-sodium-yttrium silicate mineral known for its striking pink, radiating, or needle-like crystal aggregates. It is primarily found in highly alkaline pegmatites, often appearing as delicate, fibrous sprays associated with other rare earth minerals.

Hardness
5
Mohs
Luster
Vitreous
Streak
White
Transparency
Translucent

Is this ashcroftine-(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 ashcroftine-(y) with a known reference. Ashcroftine-(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. Ashcroftine-(Y) leaves a white streak.
  • 3
    Read the luster
    Hold the specimen under a strong light. Ashcroftine-(Y) typically shows a vitreous luster.
  • 4
    Match the color range
    Compare against the expected color range: pink, rose-red, colorless.
  • 5
    Look at form & habit
    Crystal system: tetragonal. Typical habit: acicular or radiating aggregates, fibrous sprays.

Often confused with

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

Often found alongside ashcroftine-(y)

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

All properties

Chemical formula
K₅Na₂₁Ca(Y,Dy)₂(CO₃)₄Si₂₈O₇₀(OH)₂·nH₂O
Mohs hardness
5
Density
2.61 g/cm³
Streak
White
Luster
Vitreous
Transparency
Translucent
Crystal system
Tetragonal
Crystal habit
Acicular or Radiating Aggregates, Fibrous Sprays
Cleavage
Good
Fluorescence
Bright White/pale Yellow Under LW UV
Rarity
Rare
Uses
Collector
Host rock
Alkaline Pegmatites

Where rockhounds find ashcroftine-(y)

Classic worldwide localities

  • Narssarssuk, Greenland
  • Khibiny Massif, Russia
  • Lovozero Massif, Russia

Field-hunting tip

Look in alkaline pegmatites country, the host setting where ashcroftine-(y) typically forms. If you start seeing microcline, aegirine, analcime in float, you are in the right ground. Field specimens usually show a acicular or radiating aggregates, fibrous sprays habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify ashcroftine-(y)?+
Mohs hardness is 5. It typically shows a vitreous luster. The streak is white. Common colors include pink, rose-red, colorless.
Where is ashcroftine-(y) found?+
Notable localities include Narssarssuk, Greenland; Khibiny Massif, Russia; Lovozero Massif, Russia.
What rocks look like ashcroftine-(y)?+
Ashcroftine-(Y) is most often confused with Scolecite, Mesolite, Thomsonite. A quick hardness test and a streak check separate the look-alikes faster than color alone.
What minerals are found with ashcroftine-(y)?+
Ashcroftine-(Y) commonly co-occurs with Microcline, Aegirine, Analcime, Eudialyte. Spotting any of these in float or country rock is a useful trip signal.
What kind of rock does ashcroftine-(y) form in?+
Ashcroftine-(Y) typically forms in alkaline pegmatites. Working float back to the host body is the standard way to chase a fresh occurrence.
What is ashcroftine-(y) used for?+
Ashcroftine-(Y) is used in collector.

Find ashcroftine-(y) on the map

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