Matsubaraite is a rare strontium-titanium silicate belonging to the chevkinite group. It is typically found as small, gray tabular crystals associated with glaucophane schist formations. It is primarily a collector's mineral known for its complex chemical structure and limited type locality in Japan.

Hardness

5.5

Mohs

Luster

Adamantine

Streak

White

Transparency

Transparent

mineralrareChevkinite Group family

Matsubaraite

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

No image

Is this matsubaraite?

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 matsubaraite with a known reference. Matsubaraite 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: adamantine.
4
Match the color range
Compare against the expected color range: blue tinted gray.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: aggregates, fan shaped, prismatic.

Often found alongside matsubaraite

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

All properties

Chemical formula: Sr₄Ti₅(Si₂O₇)₂O₈
Mohs hardness: 5.5
Density: 4.13 g/cm³
Colors: Blue tinted gray
Streak: White
Luster: Adamantine
Transparency: Transparent
Crystal system: Monoclinic
Crystal habit: Aggregates, fan shaped, prismatic
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: From a boulder of Ti-bearing jadeitite, the product of late stage high-P/T metamorphism

Where rockhounds find matsubaraite

Classic worldwide localities

Itoigawa-Ohmi, Niigata Prefecture, Japan (type locality)

Field-hunting tip

Where it forms: From a boulder of Ti-bearing jadeitite, the product of late stage high-P/T metamorphism. If you start seeing jadeite, natrolite, lamprophyllite in float, you are in the right ground. Typical habit: aggregates, fan shaped, prismatic. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify matsubaraite?+

Mohs hardness is 5.5. Luster: adamantine. The streak is white. Common colors include blue tinted gray.

Where is matsubaraite found?+

Notable localities include Itoigawa-Ohmi, Niigata Prefecture, Japan (type locality).

What minerals are found with matsubaraite?+

Matsubaraite commonly co-occurs with Jadeite, Natrolite, Lamprophyllite, Titanite, Zircon, Rutile. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does matsubaraite form in?+

Where it forms: From a boulder of Ti-bearing jadeitite, the product of late stage high-P/T metamorphism. Working float back to the host body is the standard way to chase a fresh occurrence.

What is matsubaraite used for?+

Matsubaraite is used in collector.

Find matsubaraite on the map

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