Pertsevite-(OH) is a rare magnesium borate mineral first discovered in the contact-metasomatic boron deposits of the Tayozhnoye iron deposit in Siberia. It typically occurs as small tabular crystals or intergrown grains within magnesium-rich skarn environments. Due to its rarity and specific formation conditions, it is primarily sought after by advanced systematic mineral collectors.

Hardness

5.5-6.5

Mohs

Luster

Vitreous

Transparency

Transparent

mineralrare

Pertsevite-(OH)

Hardness: 5.5-6.5
Luster: Vitreous
Transparency: Transparent

No image

Is this pertsevite-(oh)?

4-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 pertsevite-(oh) with a known reference. Pertsevite-(OH) sits at Mohs 5.5-6.5, softer than the next harder reference, harder than the previous one.
2
Read the luster
Hold the specimen under a strong light. Luster: vitreous.
3
Match the color range
Compare against the expected color range: colorless.
4
Look at form & habit
Crystal system: orthorhombic. Typical habit: tabular crystals, anhedral grains.

Often confused with

Pertsevite-(OH) vs. its common look-alikes, and how to tell them apart in the field.

How to tell apart: Luster reads vitreous on Pertsevite-(OH) and submetallic on Ludwigite.

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Often found alongside pertsevite-(oh)

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

All properties

Chemical formula: Mg₂BO₃(OH)
Mohs hardness: 5.5-6.5
Density: 3.12 g/cm³
Colors: Colorless
Luster: Vitreous
Transparency: Transparent
Crystal system: Orthorhombic
Crystal habit: Tabular crystals, anhedral grains
Cleavage: Imperfect
Rarity: Rare
Uses: Collector
Host rock: In ludwigite-kotoite magnesian skarn

Where rockhounds find pertsevite-(oh)

Classic worldwide localities

Snezhnoye deposit, East Verkhoyan’ye region, 250-300 km east of Verhoyansk, Sakha-Yakutia and at Gonochan, Dzhugdzhur Ridge, 60-70 km from the Okhotsk Sea coast, Far East, Russia

Field-hunting tip

Where it forms: In ludwigite-kotoite magnesian skarn. If you start seeing kotoite, szaibelyite, ludwigite-azoproite in float, you are in the right ground. Typical habit: tabular crystals, anhedral grains. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify pertsevite-(oh)?+

Mohs hardness is 5.5-6.5. Luster: vitreous. Common colors include colorless.

Where is pertsevite-(oh) found?+

Notable localities include Snezhnoye deposit, East Verkhoyan’ye region, 250-300 km east of Verhoyansk, Sakha-Yakutia and at Gonochan, Dzhugdzhur Ridge, 60-70 km from the Okhotsk Sea coast, Far East, Russia.

What rocks look like pertsevite-(oh)?+

Pertsevite-(OH) is most often confused with Pertsevite-(F), Ludwigite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with pertsevite-(oh)?+

Pertsevite-(OH) commonly co-occurs with Kotoite, Szaibelyite, Ludwigite-azoproite, Clinohumite, Hydroxylclinohumite, Forsterite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does pertsevite-(oh) form in?+

Where it forms: In ludwigite-kotoite magnesian skarn. Working float back to the host body is the standard way to chase a fresh occurrence.

What is pertsevite-(oh) used for?+

Pertsevite-(OH) is used in collector.

Find pertsevite-(oh) on the map

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