What is Tourmaline?


Tourmaline is a crystalline boron silicate mineral that comes in a variety of colors. It’s primarily found in Brazil, Sri Lanka, and parts of Africa. Tourmaline is often used as a gemstone and is a popular choice for jewelry due to its wide range of colors and spiritual significance.

Tourmaline is a colorful gemstone that comes in a variety of hues, including black, blue, green, pink, and multicolored. Its wide range of colors and lustrous appearance make it a popular choice for jewelry and decorative items. The stone is often used in rings, necklaces, and pendants, and is sometimes used to make beads.

Gemstone Properties

Chemical ClassificationInorganic - Silicate (Cyclosilicate)
ColorComes in a wide range of colors, including black, brown, green, pink, blue, yellow, and even watermelon (green on the outside, pink on the inside).
TransparencyVaries from transparent to opaque.
OccurrenceBrazil, Madagascar, Afghanistan.
FormationTourmaline is formed in pegmatites and metamorphic rocks, and sometimes in granites and volcanic rocks.
DiaphaneityTransparent to translucent
CleavagePoor in two directions
Mohs Hardness7 to 7.5.
Specific GravityApproximately 3.06 to 3.10.
Diagnostic PropertiesPrismatic crystals, often with striations, various colors.
Chemical Composition(Ca,K,Na,[])(Al,Fe,Li,Mg,Mn)3(Al,Cr, Fe,V)6 (BO3)3(Si,Al,B)6O18(OH,F)4
PleochroismStrong; different colors are visible from different angles.
Crystal SystemTrigonal
Optical PropertiesUniaxial (-)
Refractive Index1.616 - 1.650
Birefringence0.017 - 0.040
2V angleMeasured: 44°