How does tourmaline produce negative ions ?

[lnsanity]

How does tourmaline produce negative ions ?

Where those negative ions come from ?

I know that negative ions is simply atoms with 1 extra electron so where they come from ?

I also know that volcanic ash also produce negative ion same question ?

 

[Sankalp Zeal]

How does tourmaline produce negative ions ?

Where those negative ions come from ?

I know that negative ions is simply atoms with 1 extra electron so where they come from ?

I also know that volcanic ash also produce negative ion same question ?

This is a very wide question.
The formula of tourmaline is this : XY₃Z₆(T₆O₁₈)(BO₃)₃V₃W

where:
X = Ca, Na, K, vacancy

Y = Li, Mg, Fe²⁺, Mn²⁺, Zn, Al, Cr³⁺, V³⁺, Fe³⁺, Ti⁴⁺, vacancy

Z = Mg, Al, Fe³⁺, Cr³⁺, V³⁺

T = Si, Al, B

B = B, vacancy

V = OH, O

W = OH, F, O

Now realize that there are lot of non metals in tourmaline.
Due to high percussion , temperature , bond energy , in water , etc , non metals in the compound dissociate into negative ions.
As you know non metals take or share electrons so they have excess of electrons.