Titanoholtite is a rare member of the dumortierite supergroup characterized by its significant titanium content. It typically occurs as slender, acicular crystals or fibrous masses in boron-rich geological environments. Because it is visually similar to dumortierite and holtite, chemical analysis is often required for definitive identification.

Hardness

7-8

Mohs

Transparency

Translucent

mineralrareDumortierite Supergroup family

Titanoholtite

Hardness: 7-8
Transparency: Translucent

Is this titanoholtite?

2-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 titanoholtite with a known reference. Titanoholtite sits at Mohs 7-8, softer than the next harder reference, harder than the previous one.
2
Look at form & habit
Crystal system: orthorhombic. Typical habit: fibrous aggregates, acicular crystals.

Often confused with

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

Often found alongside titanoholtite

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

All properties

Chemical formula: (Al,Ti,☐)₇(BO₃)(SiO₄)₃O₃
Mohs hardness: 7-8
Density: 3.66 g/cm³
Transparency: Translucent
Crystal system: Orthorhombic
Crystal habit: Fibrous aggregates, acicular crystals
Rarity: Rare
Uses: Collector
Host rock: In the internal portion of a complex zoned granitic pegmatite

Where rockhounds find titanoholtite

Classic worldwide localities

Marta mine, northern part of Szklana Hill, Szklary serpentinite massif, ~60 km south of Wroclaw, Lower Silesia, Poland

Field-hunting tip

Where it forms: In the internal portion of a complex zoned granitic pegmatite. If you start seeing holtite, microcline, quartz in float, you are in the right ground. Typical habit: fibrous aggregates, acicular crystals. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify titanoholtite?+

Mohs hardness is 7-8.

Where is titanoholtite found?+

Notable localities include Marta mine, northern part of Szklana Hill, Szklary serpentinite massif, ~60 km south of Wroclaw, Lower Silesia, Poland.

What rocks look like titanoholtite?+

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

What minerals are found with titanoholtite?+

Titanoholtite commonly co-occurs with Holtite, Microcline, Quartz, Muscovite, Spessartine, Chrysoberyl. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does titanoholtite form in?+

Where it forms: In the internal portion of a complex zoned granitic pegmatite. Working float back to the host body is the standard way to chase a fresh occurrence.

What is titanoholtite used for?+

Titanoholtite is used in collector.

Find titanoholtite on the map

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