Coskrenite-(Ce) is a rare cerium oxalate mineral found primarily in alkaline igneous environments. It typically forms as delicate, tabular, pale yellow crystals or radiating clusters within vugs or cavities of pegmatite host rocks.

Hardness

2-3

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Coskrenite-(Ce)

Hardness: 2-3
Luster: Vitreous
Streak: White
Transparency: Transparent

Is this coskrenite-(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 coskrenite-(ce) with a known reference. Coskrenite-(Ce) sits at Mohs 2-3, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: white.
3
Read the luster
Hold the specimen under a strong light. Luster: vitreous.
4
Match the color range
Compare against the expected color range: pink, very pale blue, cream.
5
Look at form & habit
Crystal system: triclinic. Typical habit: tabular, water soluble, wedge shaped.

Often confused with

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

mineral

Weddellite

Mohs ~4

How to tell apart: Weddellite is the harder of the two (Mohs ~4 vs. 2-3).

Often found alongside coskrenite-(ce)

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

All properties

Chemical formula: Ce₂(SO₄)₂((C₂)O₄)·8H₂O
Mohs hardness: 2-3
Density: 2.881 g/cm³
Colors: PinkVery pale blueCream
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Triclinic
Crystal habit: Tabular, water soluble, wedge shaped
Cleavage: On {001}, perfect
Rarity: Rare
Uses: Collector
Host rock: Formed by weathering of pyritiferous phyllite with evaporation of the resulting sulfate-rich solutions in soil, the rare earths probably derived from monazite and xenotime

Where rockhounds find coskrenite-(ce)

Classic worldwide localities

Alum Cave Bluff, Great Smoky Mountains National Park, Tennessee, USA

Field-hunting tip

Where it forms: Formed by weathering of pyritiferous phyllite with evaporation of the resulting sulfate-rich solutions in soil, the rare earths probably derived from monazite and xenotime. If you start seeing epsomite, apjohnite in float, you are in the right ground. Typical habit: tabular, water soluble, wedge shaped. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify coskrenite-(ce)?+

Mohs hardness is 2-3. Luster: vitreous. The streak is white. Common colors include pink, very pale blue, cream.

Where is coskrenite-(ce) found?+

Notable localities include Alum Cave Bluff, Great Smoky Mountains National Park, Tennessee, USA.

What rocks look like coskrenite-(ce)?+

Coskrenite-(Ce) is most often confused with Weddellite, Whewellite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with coskrenite-(ce)?+

Coskrenite-(Ce) commonly co-occurs with Epsomite, Apjohnite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does coskrenite-(ce) form in?+

Where it forms: Formed by weathering of pyritiferous phyllite with evaporation of the resulting sulfate-rich solutions in soil, the rare earths probably derived from monazite and xenotime. Working float back to the host body is the standard way to chase a fresh occurrence.

What is coskrenite-(ce) used for?+

Coskrenite-(Ce) is used in collector.

Find coskrenite-(ce) on the map

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