Edtollite is a rare calcium-magnesium-iron garnet species discovered in metasomatic rocks. It typically occurs as small, dark brown dodecahedral crystals that are visually similar to other garnet group members, often requiring chemical analysis for definitive identification.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrareGarnet Group family

Edtollite

Hardness: 7
Luster: Vitreous
Streak: White
Transparency: Translucent

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Is this edtollite?

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 edtollite with a known reference. Edtollite sits at Mohs 7 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Edtollite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Edtollite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: dark brown, reddish-brown.
5
Look at form & habit
Crystal system: cubic. Typical habit: dodecahedral crystals.

Often confused with

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

Often found alongside edtollite

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

All properties

Chemical formula: Ca₃(Mg₄Fe₂)(SiO₄)₃
Mohs hardness: 7
Density: 3.8-4.0 g/cm³
Colors: Dark Brown Reddish-brown
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Cubic
Crystal habit: Dodecahedral Crystals
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Skarn
Typical price: $50-300 per specimen

Where rockhounds find edtollite

Classic worldwide localities

Kola Peninsula, Russia
Srednyaya Padma, Russia

Field-hunting tip

Look in skarn country — that is the host setting where edtollite typically forms. If you start seeing diopside, calcite, magnetite in float, you are in the right ground. Field specimens usually show a dodecahedral crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify edtollite?+

Mohs hardness is 7. It typically shows a vitreous luster. The streak is white. Common colors include dark brown, reddish-brown.

Where is edtollite found?+

Notable localities include Kola Peninsula, Russia; Srednyaya Padma, Russia.

How much is edtollite worth?+

Typical asking prices fall in the range of $50-300 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like edtollite?+

Edtollite is most often confused with Andradite, Grossularite Garnet. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with edtollite?+

Edtollite commonly co-occurs with Diopside, Calcite, Magnetite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does edtollite form in?+

Edtollite typically forms in skarn. Working float back to the host body is the standard way to chase a fresh occurrence.

What is edtollite used for?+

Edtollite is used in collector.

Find edtollite on the map

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