Tourmaline

UNB-2020-0065Minerals » Silicates » Cyclosilicates

Description

Original Description: *Incomplete. Tourmaline (Na(Mg,Fe)3Al6(BO3)3(Si6O18)(OH,F)4) can be black (Schorl), blue (Indicolite), pink and red (Rubellite), brown (Dravite), green, multicoloured and white (rare). Lustre is vitreous and streak is white. Hardness is 7 to 7 1/2. Tourmaline usually occurs as short to long prismatic crystals with rounded triangular cross sections with striations along the length of the crystal faces. Tourmaline can also be radiating, columnar or compact.

Specifications

Object name	Tourmaline
ID	UNB-2020-0065
Legal status	Permanent collection
Category	Mineral
Classification	Mineral group: Silicates Sub-group: Cyclosilicates
Composition	BaTiSi3O9 (Mg,Fe)2Al3(Si5AlO18) (Ca,Fe,Mg)3Al2BO3Si4O12(OH) Be3Al2(Si6O18) Be3Al2(Si6O18) Na(Li,Al)3Al6(BO3)3Si6O18(OH)4 Na15Ca6(Fe2+,Mn2+)3Zr3Si25O733(CO3) (Ca,Na)19(Al,Mg,Fe)13(SiO4)10(Si2O7)4(OH,F,O)10 (Na,Ca)(Fe,Mg,Li,Al)3Al6(BO3)3(Si6O18)(OH)4 Be₃Al₂(SiO₃)₆ A(D3)G6(T6O18)(BO3)3X3Z
Origin	Unknown
Pieces	1
Partial	No

Publications

Chesterman, C.W. 1979. Audubon Society, Field Guide to North American Rocks and Minerals. Knopf.