Hungchaoite is a rare magnesium borate mineral typically found as small, platy crystals or efflorescent crusts in saline lake beds. It is highly soluble and hygroscopic, requiring careful storage in a dry environment to prevent degradation.

Hardness

2-2.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Hungchaoite

Hardness: 2-2.5
Luster: Vitreous
Streak: White
Transparency: Transparent

Is this hungchaoite?

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 hungchaoite with a known reference. Hungchaoite sits at Mohs 2-2.5, 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: colorless, white.
5
Look at form & habit
Crystal system: triclinic. Typical habit: platy crystals, crusts, aggregates.

Often confused with

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

How to tell apart: Hungchaoite is noticeably harder (Mohs 2-2.5 vs. 1); luster reads vitreous on Hungchaoite and pearly on Sassolite.

Compare →

Often found alongside hungchaoite

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

All properties

Chemical formula: MgB₄O₅(OH)₄·7H₂O
Mohs hardness: 2-2.5
Density: 1.706 g/cm³
Colors: Colorless White
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Triclinic
Crystal habit: Platy crystals, crusts, aggregates
Cleavage: {111}, perfect; {111}, good; {010}, imperfect
Rarity: Rare
Uses: Collector
Host rock: In lacustrine saline borate deposits (China); an efflorescence on weathered colemanite and priceite veins (Death Valley, California, USA)

Where rockhounds find hungchaoite

Classic worldwide localities

Hard Scramble claim, in the Furnace Creek district, Death Valley, Inyo Co., California, USA

Field-hunting tip

Where it forms: In lacustrine saline borate deposits (China); an efflorescence on weathered colemanite and priceite veins (Death Valley, California, USA). If you start seeing ulexite, hydroboracite, szaibélyite in float, you are in the right ground. Typical habit: platy crystals, crusts, aggregates. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify hungchaoite?+

Mohs hardness is 2-2.5. Luster: vitreous. The streak is white. Common colors include colorless, white.

Where is hungchaoite found?+

Notable localities include Hard Scramble claim, in the Furnace Creek district, Death Valley, Inyo Co., California, USA.

What rocks look like hungchaoite?+

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

What minerals are found with hungchaoite?+

Hungchaoite commonly co-occurs with Ulexite, Hydroboracite, Szaibélyite, Gypsum, Ginorite, Mcallisterite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does hungchaoite form in?+

Where it forms: In lacustrine saline borate deposits (China); an efflorescence on weathered colemanite and priceite veins (Death Valley, California, USA). Working float back to the host body is the standard way to chase a fresh occurrence.

What is hungchaoite used for?+

Hungchaoite is used in collector.

Find hungchaoite on the map

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