Thortveitite is a rare scandium-rich silicate mineral primarily found in granitic pegmatites. It typically occurs as elongated, gray-green prisms and is highly prized by mineral collectors as the primary industrial source of scandium.

Hardness

6-7

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrare

Thortveitite

Hardness: 6-7
Luster: Vitreous
Streak: White
Transparency: Translucent

Is this thortveitite?

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 thortveitite with a known reference. Thortveitite sits at Mohs 6-7, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Thortveitite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Thortveitite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: grayish-green, gray, greenish-white.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: prismatic crystals, often elongated and striated.

Often confused with

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

How to tell apart: Thortveitite is noticeably harder (Mohs 6-7 vs. 5).

How to tell apart: Luster reads vitreous on Thortveitite and adamantine on Zircon.

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Often found alongside thortveitite

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

All properties

Chemical formula: (Sc,Y)₂Si₂O₇
Mohs hardness: 6-7
Density: 3.27-3.43 g/cm³
Colors: Grayish-green Gray Greenish-white
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Monoclinic
Crystal habit: Prismatic Crystals, Often Elongated and Striated
Cleavage: Distinct
Rarity: Rare
Uses: Collector, Source of Scandium
Host rock: Granite Pegmatites
Typical price: $100-500 thumbnail, $500+ specimen grade

Where rockhounds find thortveitite

Classic worldwide localities

Iveland, Norway
Madagascar
Hittero, Norway
Arizona, USA
New Mexico, USA

Field-hunting tip

Look in granite pegmatites country, the host setting where thortveitite typically forms. If you start seeing microcline, beryl, monazite in float, you are in the right ground. Field specimens usually show a prismatic crystals, often elongated and striated habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify thortveitite?+

Mohs hardness is 6-7. It typically shows a vitreous luster. The streak is white. Common colors include grayish-green, gray, greenish-white.

Where is thortveitite found?+

Notable localities include Iveland, Norway; Madagascar; Hittero, Norway; Arizona, USA; New Mexico, USA.

How much is thortveitite worth?+

Typical asking prices fall in the range of $100-500 thumbnail, $500+ specimen grade. Quality, size, and provenance can move individual specimens well outside that range.

Is thortveitite safe to handle?+

This mineral is radioactive. Contains minor radioactive elements; handle with care and wash hands after contact. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like thortveitite?+

Thortveitite is most often confused with Beryl, Apatite, Zircon. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with thortveitite?+

Thortveitite commonly co-occurs with Microcline, Beryl, Monazite, Ilmenite, Gadolinite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does thortveitite form in?+

Thortveitite typically forms in granite pegmatites. Working float back to the host body is the standard way to chase a fresh occurrence.

What is thortveitite used for?+

Thortveitite is used in collector, source of scandium.

Find thortveitite on the map

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