Tinzenite is a member of the axinite group characterized by its significant manganese content, which gives it distinctive warm yellow to brownish-orange hues. It is typically found in manganese-rich silicate rocks formed through regional metamorphism. Collectors look for its wedge-shaped, triclinic crystal habits, which are rare and prized from classic localities like Switzerland and Franklin, New Jersey.

Hardness

6.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrareAxinite Group family

Tinzenite

Hardness: 6.5
Luster: Vitreous
Streak: White
Transparency: Translucent

Is this tinzenite?

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 tinzenite with a known reference. Tinzenite sits at Mohs 6.5, 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: yellow, orange red.
5
Look at form & habit
Crystal system: triclinic. Typical habit: columnar.

Often confused with

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

Often found alongside tinzenite

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

All properties

Chemical formula: (Ca,Mn)₃Al₂BSi₄O₁₅(OH)
Mohs hardness: 6.5
Density: 3.355-3.433 g/cm³
Colors: Yellow Orange red
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Triclinic
Crystal habit: Columnar
Cleavage: {100} good; {001}, {110}, {011}, poor (by analogy to the axinite group)
Rarity: Rare
Uses: Collector
Host rock: In metamorphosed manganese-bearing ophiolites (Liguria, Italy); in quartz veins in cherts of the greenschist facies (Akatore, New Zealand)

Where rockhounds find tinzenite

Classic worldwide localities

Tinzen, in the Val d'Err, Graubünden, Switzerland
Cassagna and Gambatesa mines, Val Graveglia, near Chiavari, Liguria, Italy
Akatore, New Zealand

Field-hunting tip

Where it forms: In metamorphosed manganese-bearing ophiolites (Liguria, Italy); in quartz veins in cherts of the greenschist facies (Akatore, New Zealand). If you start seeing braunite, quartz in float, you are in the right ground. Typical habit: columnar. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify tinzenite?+

Mohs hardness is 6.5. Luster: vitreous. The streak is white. Common colors include yellow, orange red.

Where is tinzenite found?+

Notable localities include Tinzen, in the Val d'Err, Graubünden, Switzerland; Cassagna and Gambatesa mines, Val Graveglia, near Chiavari, Liguria, Italy; Akatore, New Zealand.

What rocks look like tinzenite?+

Tinzenite is most often confused with Axinite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with tinzenite?+

Tinzenite commonly co-occurs with Braunite, Quartz. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does tinzenite form in?+

Where it forms: In metamorphosed manganese-bearing ophiolites (Liguria, Italy); in quartz veins in cherts of the greenschist facies (Akatore, New Zealand). Working float back to the host body is the standard way to chase a fresh occurrence.

What is tinzenite used for?+

Tinzenite is used in collector.

Find tinzenite on the map

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