Kirschsteinite is a rare calcium-iron silicate member of the olivine group that typically occurs in alkalic igneous rocks. It is most often found as microscopic inclusions or grains, making high-quality visible specimens highly sought after by collectors.

Hardness

5.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrareOlivine Group family

Kirschsteinite

Hardness: 5.5
Luster: Vitreous
Streak: White
Transparency: Transparent

Is this kirschsteinite?

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 kirschsteinite with a known reference. Kirschsteinite sits at Mohs 5.5, 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, light green.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: granular, prismatic crystals.

Often confused with

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

How to tell apart: Fayalite is the harder of the two (Mohs 6.5-7 vs. 5.5).

How to tell apart: Forsterite is the harder of the two (Mohs 7 vs. 5.5).

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Often found alongside kirschsteinite

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

All properties

Chemical formula: CaFeSiO₄
Mohs hardness: 5.5
Density: 3.434 g/cm³
Colors: Colorless Light green
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Orthorhombic
Crystal habit: Granular, prismatic crystals
Cleavage: Imperfect
Rarity: Rare
Uses: Collector
Host rock: In melilite-nephelinite lava (Mt. Shaheru, Congo); in calcareous skarn (Tazheran massif, Russia)

Where rockhounds find kirschsteinite

Classic worldwide localities

Mt. Shaheru, the extinct southern cone of Mt. Nyiragongo, Kivu Province, Congo (Zaire)
Wessels mine, near Kuruman, Cape Province, South Africa
Tazheran alkalic massif, west of Lake Baikal, eastern Siberia, Russia

Field-hunting tip

Where it forms: In melilite-nephelinite lava (Mt. Shaheru, Congo); in calcareous skarn (Tazheran massif, Russia). If you start seeing melilite, nepheline, clinopyroxene in float, you are in the right ground. Typical habit: granular, prismatic crystals. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify kirschsteinite?+

Mohs hardness is 5.5. Luster: vitreous. The streak is white. Common colors include colorless, light green.

Where is kirschsteinite found?+

Notable localities include Mt. Shaheru, the extinct southern cone of Mt. Nyiragongo, Kivu Province, Congo (Zaire); Wessels mine, near Kuruman, Cape Province, South Africa; Tazheran alkalic massif, west of Lake Baikal, eastern Siberia, Russia.

What rocks look like kirschsteinite?+

Kirschsteinite is most often confused with Monticellite, Fayalite, Forsterite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with kirschsteinite?+

Kirschsteinite commonly co-occurs with Melilite, Nepheline, Clinopyroxene, Kalsilite, Götzenite, Combeite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does kirschsteinite form in?+

Where it forms: In melilite-nephelinite lava (Mt. Shaheru, Congo); in calcareous skarn (Tazheran massif, Russia). Working float back to the host body is the standard way to chase a fresh occurrence.

What is kirschsteinite used for?+

Kirschsteinite is used in collector.

Find kirschsteinite on the map

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