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

No image

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, 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.