Diaoyudaoite is a rare sodium aluminate mineral discovered in heavy mineral sands. It typically occurs as small, colorless tabular crystals and is noted for its unique composition relative to more common aluminum-bearing minerals.

Hardness

3.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Diaoyudaoite

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

Is this diaoyudaoite?

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 diaoyudaoite with a known reference. Diaoyudaoite 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. Diaoyudaoite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Diaoyudaoite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: colorless, white.
5
Look at form & habit
Crystal system: hexagonal. Typical habit: tabular crystals.

Often confused with

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

mineral

Corundum

Mohs 9

How to tell apart: Corundum is the harder of the two (Mohs 9 vs. 3.5).

How to tell apart: Spinel is the harder of the two (Mohs 8 vs. 3.5).

Compare →

Often found alongside diaoyudaoite

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

All properties

Chemical formula: NaAl₁₁O₁₇
Mohs hardness: 3.5
Density: 3.31 g/cm³
Colors: Colorless White
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Hexagonal
Crystal habit: Tabular Crystals
Cleavage: Perfect
Rarity: Rare
Uses: Collector
Host rock: Sedimentary Deposits
Typical price: expensive due to extreme scarcity

Where rockhounds find diaoyudaoite

Classic worldwide localities

Diaoyu Islands, East China Sea

Field-hunting tip

Look in sedimentary deposits country — that is the host setting where diaoyudaoite typically forms. If you start seeing corundum, spinel, magnetite in float, you are in the right ground. Field specimens usually show a tabular crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify diaoyudaoite?+

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

Where is diaoyudaoite found?+

Notable localities include Diaoyu Islands, East China Sea.

How much is diaoyudaoite worth?+

Typical asking prices fall in the range of expensive due to extreme scarcity. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like diaoyudaoite?+

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

What minerals are found with diaoyudaoite?+

Diaoyudaoite commonly co-occurs with corundum, spinel, magnetite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does diaoyudaoite form in?+

Diaoyudaoite typically forms in sedimentary deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is diaoyudaoite used for?+

Diaoyudaoite is used in collector.

Find diaoyudaoite on the map

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