Orange crystal aggregates of the extremely rare niobium mineral changbaiite in ryolite rock matrix from Round Top Prospects, Sierra Blanca, Hudspeth County, Texas, United States of America. Three faces of the specimen are polished because it was analyzed by the former owner of the specimen, the Vandenbrouck Museum. — Photo: David Hospital · CC BY-SA 4.0
Changbaiite
A lead niobium oxide (PbNb₂O₆) named for the Changbai mountains region.
Intro adapted from Wikipedia (CC BY-SA).
Changbaiite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula PbNb₂O₆.
It crystallizes in the hexagonal crystal system (space group R3m).
Key properties: Mohs hardness 5.3; specific gravity 6.48; White streak; Adamantine to pearly luster; optically uniaxial.
IMA symbol Chg, IMA status: approved, named in 1978.
Found in kaolinite-filled veins and cavities in a potassic granite.
It is found associated with Kaolinite, quartz, potassic feldspar.
The name refers to Changbai Mountain, China, on which the mineral occurs.