Card No: 12283       Created: 10/01/25    Last edition: 27/03/2026

Name: TOURMALINE
Specification: [17], structure type - tourmaline, DN
Formula: (Na,Ca)0.7(Al,Li,Mn)3Al6(Si,Al)6O18[BO3]3(OH,O)4
Symmetry Class: trigonal
Space Group: R 3m
Unit Cell
Parameters:
a = 15.8313 | c = 7.1842
Number of Formula Unit: Z = 3Unit Cell Volume, Å3: Vc = 1559.35
Number of Atomic Position
per full Unit Cell
:
P/U = 159 Molar Volume, cm3/mol: Vm = 313.09
Number of Reflexes used in
Structure Determination
:

NR = 1733
X-ray density, g/cm3: p = 2.99
R-factor: R = 0.0166MU, 1/cm: µ = 136.353
Wave Length for Calculated
Powder Diffraction Patterns
:
Co=1.78892Mass attenuation coefficient,
cm2/g
:
µ/p = 45.573
Theta-Interval for CPDP: T/I = 1-45