Changbaiite (Formula- PbNb2O) is a member of the oxide mineral class in which the mineral contains oxygen which is grouped along with one or two metal ion. It is a trigonal-ditrigonal pyramidal mineral containing lead, niobium, and oxygen. Normally it is colorless or sometimes appears in different schemes of colors like cream white, pale brown, yellowish-brown, pale yellowish-green with white streaks and adamantine to pearly luster.
Changbaiite is classified as a multiple Oxide XY2O6 and it generally has an ionic bond. Furthermore, it is also orthorhombic at a temperature of 25°C and it changes to orthorhombic-tetragonal at 570 °C.
- Category: Oxide minerals
- Formula: PbNb2O6
- Crystal system: Trigonal
- Crystal class: Ditrigonal pyramidal (3m) (same H-M symbol)
Changbaiite has a trigonal crystal system and a space group of R3m. Its lattice dimensions are a= 10.499 Å c = 11.553 Å. Changbaiite can be found as a small crystal with a tabular or spherules crystal shape. It can get up to 5mm in size and averages from 0.2 to 0.4 mm. Changbaiite’s trigonal crystals show 3m symmetry and are bound, in the sequence of lessening prominence.
- Formula mass: 489.01 gram/mol
- Color: Colorless, Cream white, Pale brown, Yellow brown, Pale yellow-green
- Crystal habit: Tabular – Form dimensions are thin in one direction.
- Mohs scale hardness: 5.5
- Luster: Adamantine – Pearly
- Streak: white
- Diaphaneity: Transparent
Occurrence: In kaolinite-filled veins and cavities in a potassic granite.
Changbaiite can be found in kaolinite cavities and potassic granite, which can be found in Tonghua, Southeastern Kirin, China. Changbaiite was named after Changbai Mountain in China because it was found there.
Association: Kaolinite, quartz, potassic feldspar.