Mineral Information and Data:

Banalsite
Na2BaAl4Si4O16 [CNMNC approved formula]

Named from a contraction of the component cation symbols: Ba, Na,Al, and Si.

IMA status : Valid species (Pre-IMA 1944) Grandfathered
CLASSIFICATION 
Dana
(8th edition) :
76.01.06.01  
  (76) Tectosilicate Al-Si Framework
  (76.01) with Al-Si frameworks
  (76.01.06) Banalsite group
  
Nickel-Strunz
(10th edition) :
09.FA.60
  (09) Silicates
  (09.F) Tektosilicates without Zeolitic H2O
  (09.FA) Tektosilicates without additional non-tetrahedral anions
  
Crystal system: Orthorhombic System
Point group (H-M): mm2 — pyramidal
Unit cell: a = 8.49Å, b = 9.98Å, c = 16.75Å
Crystal Habit: Very rarely showing traces of crystal faces; coarsely crystalline to compact, massive.
  
Color: White
Diaphaneity: Translucent to transparent in thin flakes
Luster: Vitreous, pearly on cleavage
Hardness (Mohs): 6.5
Measured Density: 3.065 g/cm3
Cleavage: Good on {110} and {001}
  
Geologic Setting: In veinlets through manganese ore and in lenses in metamorphosed mudstone (Benallt mine, Wales).
Mineral Association: Tephroite, alleghanyite, jacobsite, barite, calcite (Benallt mine, Wales)
  

<<< BACK TO MINERAL SEARCH