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.
|Chemical Classification||Inorganic - Silicate (Cyclosilicate)|
|Color||Comes in a wide range of colors, including black, brown, green, pink, blue, yellow, and even watermelon (green on the outside, pink on the inside).|
|Transparency||Varies from transparent to opaque.|
|Occurrence||Brazil, Madagascar, Afghanistan.|
|Formation||Tourmaline is formed in pegmatites and metamorphic rocks, and sometimes in granites and volcanic rocks.|
|Diaphaneity||Transparent to translucent|
|Cleavage||Poor in two directions|
|Mohs Hardness||7 to 7.5.|
|Specific Gravity||Approximately 3.06 to 3.10.|
|Diagnostic Properties||Prismatic 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|
|Pleochroism||Strong; different colors are visible from different angles.|
|Optical Properties||Uniaxial (-)|
|Refractive Index||1.616 - 1.650|
|Birefringence||0.017 - 0.040|
|2V angle||Measured: 44°|