Magnesionigerite-6N6S is a rare complex oxide mineral characterized by its extreme hardness and occurrence in tin-bearing deposits. It typically forms small tabular, hexagonal crystals that can be difficult to distinguish from common spinels or corundum without laboratory analysis.

Hardness

8-8.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrareNigerite Group family

Magnesionigerite-6N6S

Hardness: 8-8.5
Luster: Vitreous
Streak: White
Transparency: Transparent

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Is this magnesionigerite-6n6s?

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 magnesionigerite-6n6s with a known reference. Magnesionigerite-6N6S sits at Mohs 8-8.5, 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: brown, light yellow, colorless.
5
Look at form & habit
Crystal system: trigonal. Typical habit: microscopic crystals, tabular.

Often confused with

Magnesionigerite-6N6S vs. its common look-alikes, and how to tell them apart in the field.

mineral

Corundum

Mohs 9

How to tell apart: Luster reads vitreous on Magnesionigerite-6N6S and adamantine to vitreous; pearly on partings on Corundum.

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Often found alongside magnesionigerite-6n6s

Minerals reported to co-occur with magnesionigerite-6n6s. Spotting these in float or country rock is a strong cue you are in the right ground.

All properties

Chemical formula: (Mg,Al,Zn)₃(Al,Sn,Fe,Fe)₈O₁₅(OH)
Mohs hardness: 8-8.5
Density: 4.22 g/cm³
Colors: Brown Light yellow Colorless
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Trigonal
Crystal habit: Microscopic crystals, tabular
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: The Mg-analog of nigerite

Where rockhounds find magnesionigerite-6n6s

Classic worldwide localities

Anhua area, Hunan, China (type locality)

Field-hunting tip

Where it forms: The Mg-analog of nigerite. If you start seeing sillimanite, gahnite, cassiterite in float, you are in the right ground. Typical habit: microscopic crystals, tabular. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify magnesionigerite-6n6s?+

Mohs hardness is 8-8.5. Luster: vitreous. The streak is white. Common colors include brown, light yellow, colorless.

Where is magnesionigerite-6n6s found?+

Notable localities include Anhua area, Hunan, China (type locality).

What rocks look like magnesionigerite-6n6s?+

Magnesionigerite-6N6S is most often confused with Corundum. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with magnesionigerite-6n6s?+

Magnesionigerite-6N6S commonly co-occurs with Sillimanite, Gahnite, Cassiterite, Quartz. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does magnesionigerite-6n6s form in?+

Where it forms: The Mg-analog of nigerite. Working float back to the host body is the standard way to chase a fresh occurrence.

What is magnesionigerite-6n6s used for?+

Magnesionigerite-6N6S is used in collector.

Find magnesionigerite-6n6s on the map

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