Tourmaline (7 x 5 x 4 cm)

24.80

Tourmaline (7 x 5 x 4 cm) froom Haapaluoma, Finland.

Category:

Description

Formula:

A(D3)G6(T6O18)(BO3)3X3Z
A = Ca, Na, K, or is vacant (large cations);

D = Al, Fe2+, Fe3+, Li, Mg2+, Mn2+ (intermediate to small cations – in valence balancing combinations when the A site is vacant);

G = Al, Cr3+, Fe3+, V3+ (small cations);

T = Si (and sometimes minor Al, B3+);

X = O and/or OH;

Z = F, O and/or OH.

System: Trigonal

Locality: Haapaluoma, Perä-Seinäjoki, Southern Ostrobothnia, Finland

Habit: Subhedral crystals

Color: Dark violet

Luster: Vitreous luster

Weight: 186.4 g

Dimensions: 7 x 5 x 4 cm

Additional information

Weight 290 g
Dimensions 160 × 140 × 115 mm