Calamine is a historical term often associated with hemimorphite or mixtures of zinc minerals. Collectors typically prize it for its unique blue-green botryoidal or crust-like habits found in oxidized zinc deposits.

Hardness

4.5-5

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralcommon

Calamine

Hardness: 4.5-5
Luster: Vitreous
Streak: White
Transparency: Transparent

Is this calamine?

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 calamine with a known reference. Calamine sits at Mohs 4.5-5, 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: white, colorless, blue, green, brown.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: botryoidal, tabular, massive.

Often confused with

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

How to tell apart: Prehnite is the harder of the two (Mohs 6-6.5 vs. 4.5-5).

How to tell apart: Quartz is the harder of the two (Mohs 7 vs. 4.5-5).

Compare →

Often found alongside calamine

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

All properties

Chemical formula: Zn₄Si₂O₇(OH)₂·H₂O
Mohs hardness: 4.5-5
Density: 3.4-3.5 g/cm³
Colors: White Colorless Blue Green Brown
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Orthorhombic
Crystal habit: Botryoidal, tabular, massive
Cleavage: Perfect in one direction
Fluorescence: Bright white or green under SW UV
Rarity: Common
Uses: Collector, Specimen, Ore of zinc
Host rock: oxidized zinc deposits

Where rockhounds find calamine

8 mapped spots

Classic worldwide localities

Mexico
Democratic Republic of the Congo
China
Namibia
United States

Field-hunting tip

Where it forms: oxidized zinc deposits. If you start seeing smithsonite, cerussite, galena in float, you are in the right ground. Typical habit: botryoidal, tabular, massive. Train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Tennessee, Utah, Connecticut. Start trip planning there.

Browse 8 U.S. spots for calamine →

More calamine photos

Common questions

How do you identify calamine?+

Mohs hardness is 4.5-5. Luster: vitreous. The streak is white. Common colors include white, colorless, blue, green.

Where is calamine found?+

Notable localities include Mexico; Democratic Republic of the Congo; China; Namibia; United States.

Can I find calamine in the United States?+

RockHoundR maps 8 calamine rockhounding spots across 6 U.S. states. The top states are Tennessee, Utah, Connecticut.

What rocks look like calamine?+

Calamine is most often confused with Smithsonite, Prehnite, Quartz. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with calamine?+

Calamine commonly co-occurs with Smithsonite, Cerussite, Galena, Sphalerite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does calamine form in?+

Where it forms: oxidized zinc deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is calamine used for?+

Calamine is used in collector, specimen, ore of zinc.

Find calamine on the map

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