Morimotoite is a rare titanium-bearing member of the garnet group typically found as small, black dodecahedral crystals. It is primarily identified in skarn environments where contact metamorphism has occurred. It is highly valued by garnet enthusiasts for its distinct chemical composition and specific locality occurrences.

Hardness

6.5-7

Mohs

Luster

Vitreous

Streak

White

Transparency

Opaque

mineralrareGarnet Group family

Morimotoite

Hardness: 6.5-7
Luster: Vitreous
Streak: White
Transparency: Opaque

No image

Is this morimotoite?

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 morimotoite with a known reference. Morimotoite sits at Mohs 6.5-7 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Morimotoite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Morimotoite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: black, brownish black.
5
Look at form & habit
Crystal system: cubic. Typical habit: dodecahedral crystals.

Often confused with

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

Often found alongside morimotoite

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

All properties

Chemical formula: Ca₃TiFeSi₃O₁₂
Mohs hardness: 6.5-7
Density: 3.75-3.85 g/cm³
Colors: Black Brownish Black
Streak: White
Luster: Vitreous
Transparency: Opaque
Crystal system: Cubic
Crystal habit: Dodecahedral Crystals
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Skarn Deposits
Typical price: $20-150 per specimen

Where rockhounds find morimotoite

Classic worldwide localities

Fuka, Okayama Prefecture, Japan
Kola Peninsula, Russia
Magnet Cove, Arkansas, USA

Field-hunting tip

Look in skarn deposits country — that is the host setting where morimotoite typically forms. If you start seeing calcite, bultfonteinite, rankinite 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 morimotoite?+

Mohs hardness is 6.5-7. It typically shows a vitreous luster. The streak is white. Common colors include black, brownish black.

Where is morimotoite found?+

Notable localities include Fuka, Okayama Prefecture, Japan; Kola Peninsula, Russia; Magnet Cove, Arkansas, USA.

How much is morimotoite worth?+

Typical asking prices fall in the range of $20-150 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like morimotoite?+

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

What minerals are found with morimotoite?+

Morimotoite commonly co-occurs with Calcite, Bultfonteinite, Rankinite, Wollastonite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does morimotoite form in?+

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

What is morimotoite used for?+

Morimotoite is used in collector.

Find morimotoite on the map

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