Elbaite
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Elbaite, a sodium, lithium, aluminium boro-silicate, with the chemical composition NaAl₆Si₆O₁₈(BO₃)₃(OH)₄, is a mineral species belonging to the six-member ring cyclosilicate tourmaline group.
Elbaite forms three series, with dravite, with... Wikipedia
Achroite: colorless
Color: Green, red to pink, blue, orange, yellow, colorless, multicolored
Crystal class: Ditrigonal pyramidal (3m); H–M symbol: (3m)
Crystal habit: Prismatic; striated
Crystal system: Trigonal
Indicolite: blue
Other characteristics: piezoelectric and pyroelectric