Photo: Ivar Leidus · CC BY-SA 4.0

Tourmaline, cyclosilicate mineral

Properties

Chemical formula

Na(Fe²⁺₃)Al₆(Si₆O₁₈)(BO₃)₃(OH)₃(OH)

Group

Silicates

Crystal system

Trigonal

Hardness (Mohs)

7

Color

—

Luster

—

Streak

—

Density

—

Cleavage

—

Fracture

—

Tenacity

—

Crystal habit

—

Transparency

—

Space group

R3m

Fluorescence

—

Magnetism

—

Radioactivity

—

Refractive index

—

Optical character

—

Birefringence

—

Pleochroism

—

Strunz classification

9.CK.05

Dana classification

61.3.1.10

IMA status

Renamed mineral (Rn)

IMA symbol

Srl

Locality

—

Type locality

—

Discovery year

—

Source: Wikidata