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, 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.