Earlandite is an extremely rare organic mineral found in marine sediments, specifically discovered in the Weddell Sea. It typically appears as small, dull-white, chalky-looking nodules or aggregates and is scientifically significant as a calcium citrate mineral formed through biological or chemical processes in seafloor deposits.

Hardness

2-3

Mohs

Luster

Dull

Streak

White

Transparency

Translucent

mineralrare

Earlandite

Hardness: 2-3
Luster: Dull
Streak: White
Transparency: Translucent

Is this earlandite?

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 earlandite with a known reference. Earlandite 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. Earlandite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Earlandite typically shows a dull luster.
4
Match the color range
Compare against the expected color range: white, colorless.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: microcrystalline aggregates.

Often confused with

Earlandite vs. its common look-alikes — and how to tell them apart in the field.

mineral

Whewellite

Mohs 2.5-3

How to tell apart: Luster reads dull on Earlandite and vitreous on Whewellite.

How to tell apart: Luster reads dull on Earlandite and vitreous on Weddellite.

Compare →

Often found alongside earlandite

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

Calcite
mineral · Mohs 3

All properties

Chemical formula: Ca₃(C₆H₅O₇)₂·4H₂O
Mohs hardness: 2-3
Density: 1.74 g/cm³
Colors: White Colorless
Streak: White
Luster: Dull
Transparency: Translucent
Crystal system: Monoclinic
Crystal habit: Microcrystalline Aggregates
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Marine Sediments
Typical price: n/a (extremely rare collector item)

Where rockhounds find earlandite

Classic worldwide localities

Weddell Sea (Antarctica)

Field-hunting tip

Look in marine sediments country — that is the host setting where earlandite typically forms. If you start seeing calcite in float, you are in the right ground. Field specimens usually show a microcrystalline aggregates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify earlandite?+

Mohs hardness is 2-3. It typically shows a dull luster. The streak is white. Common colors include white, colorless.

Where is earlandite found?+

Notable localities include Weddell Sea (Antarctica).

How much is earlandite worth?+

Typical asking prices fall in the range of n/a (extremely rare collector item). Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like earlandite?+

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

What minerals are found with earlandite?+

Earlandite commonly co-occurs with Calcite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does earlandite form in?+

Earlandite typically forms in marine sediments. Working float back to the host body is the standard way to chase a fresh occurrence.

What is earlandite used for?+

Earlandite is used in collector.

Find earlandite on the map

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