Magnesiokoritnigite is a rare secondary arsenate mineral typically found as a oxidation product in polymetallic deposits. It most commonly presents as small, delicate bladed crystals or radiating sprays and is highly prized by advanced mineral collectors for its scarcity.

Hardness

3-4

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrareKoritnigite Group family

Magnesiokoritnigite

Hardness: 3-4
Luster: Vitreous
Streak: White
Transparency: Transparent

Is this magnesiokoritnigite?

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

Often confused with

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

Often found alongside magnesiokoritnigite

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

All properties

Chemical formula: Mg(AsO₃OH)·H₂O
Mohs hardness: 3-4
Density: 3.32 g/cm³
Colors: Colorless White Pale Pink
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Triclinic
Crystal habit: Bladed Crystals, Radial Aggregates
Cleavage: Perfect On {010}
Rarity: Rare
Uses: Collector
Host rock: Oxidized Hydrothermal Polymetallic Ore Deposits
Typical price: $50-300 per micro-specimen

Where rockhounds find magnesiokoritnigite

Classic worldwide localities

Tsumeb Mine, Namibia

Field-hunting tip

Look in oxidized hydrothermal polymetallic ore deposits country — that is the host setting where magnesiokoritnigite typically forms. If you start seeing tsumcorite, arseniosiderite, quartz in float, you are in the right ground. Field specimens usually show a bladed crystals, radial aggregates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify magnesiokoritnigite?+

Mohs hardness is 3-4. It typically shows a vitreous luster. The streak is white. Common colors include colorless, white, pale pink.

Where is magnesiokoritnigite found?+

Notable localities include Tsumeb Mine, Namibia.

How much is magnesiokoritnigite worth?+

Typical asking prices fall in the range of $50-300 per micro-specimen. Quality, size, and provenance can move individual specimens well outside that range.

Is magnesiokoritnigite safe to handle?+

It contains toxic constituents. Contains arsenic, which is toxic; handle with care, wash hands after touching, and avoid creating dust. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like magnesiokoritnigite?+

Magnesiokoritnigite is most often confused with Koritnigite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with magnesiokoritnigite?+

Magnesiokoritnigite commonly co-occurs with Tsumcorite, Arseniosiderite, Quartz. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does magnesiokoritnigite form in?+

Magnesiokoritnigite typically forms in oxidized hydrothermal polymetallic ore deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is magnesiokoritnigite used for?+

Magnesiokoritnigite is used in collector.

Find magnesiokoritnigite on the map

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