Sakhaite is a rare borate mineral found almost exclusively in contact metasomatic skarn deposits. It is best identified by its bright yellow fluorescence under shortwave UV light and its occurrence alongside other magnesium-borate species.

Hardness

Mohs

Luster

Vitreous to slightly greasy

Streak

White

Transparency

Transparent

mineralrare

Sakhaite

Hardness: 5
Luster: Vitreous to slightly greasy
Streak: White
Transparency: Transparent

Is this sakhaite?

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 sakhaite with a known reference. Sakhaite sits at Mohs 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 to slightly greasy.
4
Match the color range
Compare against the expected color range: colorless, gray, gray white.
5
Look at form & habit
Crystal system: cubic. Typical habit: euhedral crystals, massive.

Often confused with

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

mineral

Calcite

Mohs 3

How to tell apart: Sakhaite is noticeably harder (Mohs 5 vs. 3).

Compare →

Often found alongside sakhaite

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

All properties

Chemical formula: Ca₄₈Mg₁₆(BO₃)₃₂(CO₃)₁₆·2(H₂O,HCl)
Mohs hardness: 5
Density: 2.78-2.83 g/cm³
Colors: Colorless Gray Gray white
Streak: White
Luster: Vitreous to slightly greasy
Transparency: Transparent
Crystal system: Cubic
Crystal habit: Euhedral crystals, massive
Cleavage: None
Fluorescence: Bright yellow under SW UV
Rarity: Rare
Uses: Collector
Host rock: In lenses replacing marble at the contact of a granitic massif with dolostone (Titovskoye deposit, Russia)

Where rockhounds find sakhaite

Classic worldwide localities

Titovskoye boron deposit, Tas-Khayakhtakh Mountains, Sakha, and at the Solongo boron deposit, Buryatia, Russia
Sayak-IV boron deposit, northeast Balkhash region, Kazakhstan
Daiy Mountain, Qiliping, Hunan Province, China
Fuka, near Bicchu, Okayama Prefecture, Japan
Kombat Cu–Pb–Ag mine, 49 km south of Tsumeb, Namibia

Field-hunting tip

Where it forms: In lenses replacing marble at the contact of a granitic massif with dolostone (Titovskoye deposit, Russia). If you start seeing kotoite, clinohumite, forsterite in float, you are in the right ground. Typical habit: euhedral crystals, massive. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify sakhaite?+

Mohs hardness is 5. Luster: vitreous to slightly greasy. The streak is white. Common colors include colorless, gray, gray white.

Where is sakhaite found?+

Notable localities include Titovskoye boron deposit, Tas-Khayakhtakh Mountains, Sakha, and at the Solongo boron deposit, Buryatia, Russia; Sayak-IV boron deposit, northeast Balkhash region, Kazakhstan; Daiy Mountain, Qiliping, Hunan Province, China; Fuka, near Bicchu, Okayama Prefecture, Japan; Kombat Cu–Pb–Ag mine, 49 km south of Tsumeb, Namibia.

What rocks look like sakhaite?+

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

What minerals are found with sakhaite?+

Sakhaite commonly co-occurs with Kotoite, Clinohumite, Forsterite, Suanite, Spinel, Ludwigite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does sakhaite form in?+

Where it forms: In lenses replacing marble at the contact of a granitic massif with dolostone (Titovskoye deposit, Russia). Working float back to the host body is the standard way to chase a fresh occurrence.

What is sakhaite used for?+

Sakhaite is used in collector.

Find sakhaite on the map

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