Thortveitite
4 in the gallery
Thortveitite is a rare mineral consisting of scandium-rich silicate, typically forming short, bladed or prismatic crystals. It often presents a pale yellow-green to olive hue and a resinous to vitreous luster, with surfaces that can show a subtle glassy sheen. Specimens frequently occur in granular to lamellar aggregates within pegmatites and mica-rich veins, and the mineral is commonly associated with other scandium-rich phases in ultrabasic and alkaline environments.
- Formula
- (Sc,Y)2Si2O7
- Rarity
- Rare
- Stability
- Stable
- Collector interest
- High Interest
- Classification notes
- Sorosilicate; epidote-group related disilicate, Strunz 9.BE
Key characteristics
- Crystal system
- monoclinic
- Mohs hardness
- 6–7
- Specific gravity
- 3.57–3.86
- Luster
- vitreous, greasy
- Transparency
- translucent, opaque
- Color
- gray, green, black, brown
- Streak
- white, gray
- Cleavage
- good
- Fracture
- conchoidal, uneven
- Crystal habit
- prismatic, granular, massive
- Classic / historic
Where Thortveitite is found
Top localities
- Norway1 specimen
- Ankazobe District1 specimen
About Thortveitite
Norway and Madagascar are among the most important sources, where high-quality thortveitite crystals have been recovered from pegmatitic pockets and hydrothermal golddish veins. While the mineral can form in fracture-filled environments, the best crystals tend to be isolated, well-formed blades or prismatic shapes that display a delicate, almost translucent character. Collectors value thortveitite for its rarity, its subtle color, and its association with scandium-rich geology, making well-crystallized specimens sought after by specialist enthusiasts.