Urea is a rare, naturally occurring organic mineral typically found as a result of organic activity in guano deposits within caves. It forms tetragonal crystals that are highly water-soluble, making it a very difficult species to preserve in typical collection environments without controlled humidity.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Urea

Also: carbamide

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

Is this urea?

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 urea with a known reference. Urea sits at Mohs 2 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Urea leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Urea typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: white, colorless.
5
Look at form & habit
Crystal system: tetragonal. Typical habit: prismatic crystals.

Often confused with

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

Often found alongside urea

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

All properties

Chemical formula: CO(NH₂)₂
Mohs hardness: 2
Density: 1.32 g/cm³
Colors: White Colorless
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Tetragonal
Crystal habit: Prismatic Crystals
Cleavage: Poor
Rarity: Rare
Uses: Industrial, Scientific Research, Collector
Host rock: Guano Deposits
Typical price: $20-100 per specimen

Where rockhounds find urea

Classic worldwide localities

guano deposits
bat caves

Field-hunting tip

Look in guano deposits country — that is the host setting where urea typically forms. If you start seeing taranakite, leucophosphite in float, you are in the right ground. Field specimens usually show a prismatic crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify urea?+

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

Where is urea found?+

Notable localities include guano deposits; bat caves.

How much is urea worth?+

Typical asking prices fall in the range of $20-100 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like urea?+

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

What minerals are found with urea?+

Urea commonly co-occurs with taranakite, leucophosphite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does urea form in?+

Urea typically forms in guano deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is urea used for?+

Urea is used in industrial, scientific research, collector.

Find urea on the map

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