Mineralpedia Details for Rankamaite
Rankamaite
- Formula
- (Na,K,Pb)(Ta,Nb,Al)4(O,OH)10
- Crystal System
- Orthorhombic
- Crystal Habit
- Massive, Fibrous, Acicular
- Cleavage
- None, None, None
- Luster
- Adamantine
- Color
- white, creamy white
- Streak
- white
- Class
- Orthorhombic - Dipyramidal
- Hardness
- 3-4
- WebMineral
- View Rankamaite
- Mindat
- View Rankamaite
Rankamaite from Mumba, Osso, Masisi, North Kivu, DR Congo
- Special Info
- Type Locality
Rankamaite is a five-locality mineral and is confined to pegmatites, however, at this locality, the mineral is found in what they call the Mumba casiterite gravels. No doubt these gravels originated in a pegmatite.
In this specimen the Rankamaite is the pearly white, fibrous crystals. The Simpsonite is the slightly translucent orange crystal grains.
Click thumbnail images for larger view.
