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, 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.