Graulichite-(Ce) is a very rare member of the beudantite group occurring as tiny yellow to brownish-yellow crystals. It is primarily found as a secondary mineral in oxidized zones of arsenate-rich ore deposits, typically requiring magnification to identify crystal form.

Hardness
4
Mohs
Luster
Resinous
Streak
Light Yellow
Transparency
Transparent

Is this graulichite-(ce)?

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 graulichite-(ce) with a known reference. Graulichite-(Ce) sits at Mohs 4, softer than the next harder reference, harder than the previous one.
  • 2
    Check the streak
    Drag the specimen across an unglazed porcelain plate. Graulichite-(Ce) leaves a light yellow streak.
  • 3
    Read the luster
    Hold the specimen under a strong light. Graulichite-(Ce) typically shows a resinous luster.
  • 4
    Match the color range
    Compare against the expected color range: light green, brownish.
  • 5
    Look at form & habit
    Crystal system: trigonal. Typical habit: microscopic crystals, crusts.

Often confused with

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

Often found alongside graulichite-(ce)

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

All properties

Chemical formula
CeFe³⁺₃(AsO₄)₂(OH)₆
Mohs hardness
4
Density
4.2-4.5 g/cm³
Streak
Light Yellow
Luster
Resinous
Transparency
Transparent
Crystal system
Trigonal
Crystal habit
Microscopic Crystals, Crusts
Cleavage
None
Rarity
Rare
Uses
Collector
Host rock
Oxidized Hydrothermal Ore Deposits

Where rockhounds find graulichite-(ce)

Classic worldwide localities

  • Wittichen, Germany

Field-hunting tip

Look in oxidized hydrothermal ore deposits country, the host setting where graulichite-(ce) typically forms. If you start seeing goethite, baryte, quartz in float, you are in the right ground. Field specimens usually show a microscopic crystals, crusts habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify graulichite-(ce)?+
Mohs hardness is 4. It typically shows a resinous luster. The streak is light yellow. Common colors include light green, brownish.
Where is graulichite-(ce) found?+
Notable localities include Wittichen, Germany.
Is graulichite-(ce) safe to handle?+
It contains toxic constituents. Contains arsenic; handle with gloves and wash hands thoroughly after handling. Do not inhale dust. Handle with care, avoid grinding or breathing dust, and store separately.
What rocks look like graulichite-(ce)?+
Graulichite-(Ce) is most often confused with Beudantite, Corkite, Segnitite. A quick hardness test and a streak check separate the look-alikes faster than color alone.
What minerals are found with graulichite-(ce)?+
Graulichite-(Ce) commonly co-occurs with Goethite, Baryte, Quartz. Spotting any of these in float or country rock is a useful trip signal.
What kind of rock does graulichite-(ce) form in?+
Graulichite-(Ce) typically forms in oxidized hydrothermal ore deposits. Working float back to the host body is the standard way to chase a fresh occurrence.
What is graulichite-(ce) used for?+
Graulichite-(Ce) is used in collector.

Find graulichite-(ce) on the map

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