Dashkovaite is a very rare magnesium formate dihydrate mineral primarily found in the ultra-alkaline rocks of the Khibiny Massif. Collectors should look for its tabular, colorless to white crystals that are typically associated with secondary minerals in pegmatite cavities.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Semitransparent

mineralrare

Dashkovaite

Hardness: 1
Luster: Vitreous
Streak: White
Transparency: Semitransparent

No image

Is this dashkovaite?

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 dashkovaite with a known reference. Dashkovaite sits at Mohs 1, 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: white.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: aggregates, fibrous.

Often confused with

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

mineral

Calcite

Mohs 3

How to tell apart: Calcite is the harder of the two (Mohs 3 vs. 1).

How to tell apart: Luster reads vitreous on Dashkovaite and subvitreous, pearly on {010} cleavages, silky if fibrous on Gypsum.

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Often found alongside dashkovaite

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

All properties

Chemical formula: Mg(HCOO)₂·2H₂O
Mohs hardness: 1
Density: 1.74 g/cm³
Colors: White
Streak: White
Luster: Vitreous
Transparency: Semitransparent
Crystal system: Monoclinic
Crystal habit: Aggregates, fibrous
Cleavage: Perfect
Rarity: Rare
Uses: Collector
Host rock: Rare, in hydrothermal veinlets in serpentine in dolomite marble

Where rockhounds find dashkovaite

Classic worldwide localities

Korshunovskoye iron–boron skarn deposit, Irkutsk district, Siberia, Russia

Field-hunting tip

Where it forms: Rare, in hydrothermal veinlets in serpentine in dolomite marble. If you start seeing shabynite, iowaite, ekaterinite in float, you are in the right ground. Typical habit: aggregates, fibrous. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify dashkovaite?+

Mohs hardness is 1. Luster: vitreous. The streak is white. Common colors include white.

Where is dashkovaite found?+

Notable localities include Korshunovskoye iron–boron skarn deposit, Irkutsk district, Siberia, Russia.

What rocks look like dashkovaite?+

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

What minerals are found with dashkovaite?+

Dashkovaite commonly co-occurs with Shabynite, Iowaite, Ekaterinite, Korshunovskite, Halite, Hydromagnesite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does dashkovaite form in?+

Where it forms: Rare, in hydrothermal veinlets in serpentine in dolomite marble. Working float back to the host body is the standard way to chase a fresh occurrence.

What is dashkovaite used for?+

Dashkovaite is used in collector.

Find dashkovaite on the map

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