Tourmaline

UNB-2020-0061Minerals » Silicates » Cyclosilicates

Description

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

Specifications

Object name	Tourmaline
ID	UNB-2020-0061
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	Brazil
Pieces	1
Partial	No

Map of Origin

Publications

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