Adamite is a secondary mineral found in the oxidation zones of zinc-rich mineral deposits. Collectors prize it for its vibrant yellow to green colors and frequently lustrous, radial crystal sprays or botryoidal crusts.

Hardness

3.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineraluncommon

Adamite

Hardness: 3.5
Luster: Vitreous
Streak: White
Transparency: Transparent

Is this adamite?

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 adamite with a known reference. Adamite sits at Mohs 3.5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Adamite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Adamite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: yellow, green, colorless, white, violet.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: bladed, drusy, botryoidal, radial clusters.

Often confused with

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

How to tell apart: Hemimorphite is the harder of the two (Mohs 4.5-5 vs. 3.5).

How to tell apart: Conichalcite is the harder of the two (Mohs 4.5 vs. 3.5); streak differs, so Adamite leaves white, Conichalcite leaves light green.

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Often found alongside adamite

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

All properties

Chemical formula: Zn₂(AsO₄)(OH)
Mohs hardness: 3.5
Density: 4.3-4.5 g/cm³
Colors: Yellow Green Colorless White Violet
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Orthorhombic
Crystal habit: Bladed, Drusy, Botryoidal, Radial Clusters
Cleavage: Distinct On {101}
Fluorescence: Often Bright Yellow-green Under SW/LW UV
Rarity: Uncommon
Uses: Collector
Host rock: Oxidized Zones of Zinc Deposits
Typical price: $20-200 for specimens depending on crystal size and color quality

Where rockhounds find adamite

Classic worldwide localities

Mapimi, Mexico
Tsumeb, Namibia
Laurion, Greece
Gold Hill, Utah, USA

Field-hunting tip

Look in oxidized zones of zinc deposits country, the host setting where adamite typically forms. If you start seeing smithsonite, hemimorphite, limonite in float, you are in the right ground. Field specimens usually show a bladed, drusy, botryoidal, radial clusters habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify adamite?+

Mohs hardness is 3.5. It typically shows a vitreous luster. The streak is white. Common colors include yellow, green, colorless, white.

Where is adamite found?+

Notable localities include Mapimi, Mexico; Tsumeb, Namibia; Laurion, Greece; Gold Hill, Utah, USA.

How much is adamite worth?+

Typical asking prices fall in the range of $20-200 for specimens depending on crystal size and color quality. Quality, size, and provenance can move individual specimens well outside that range.

Is adamite safe to handle?+

It contains toxic constituents. Contains arsenic, which is toxic if ingested or inhaled as dust. Wash hands thoroughly after handling and avoid grinding or creating mineral dust. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like adamite?+

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

What minerals are found with adamite?+

Adamite commonly co-occurs with Smithsonite, Hemimorphite, Limonite, Austinite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does adamite form in?+

Adamite typically forms in oxidized zones of zinc deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is adamite used for?+

Adamite is used in collector.

Find adamite on the map

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