TOURMALINE COLOR CHANGE 4.25 CTS 19387 – NATURAL CEYLON GEMSTONE

100% Natural – Not treated in any way.
Rare Collectors Gem
Suitable for Museums,Institutions and Students of Gemology.
Will make a Gorgeous Ring or Pendent accented with Diamonds.
Gem with High Lustre and Good Clarity.
Large Sizes are Extremely Rare!
A Gem of Lasting Beauty.
Tourmaline Color-change – A unique color miracle displaying a Mix of Red, Yellow, Gold and Green
– Rare type of Tourmaline

Refractive Index:1.624(+.005,-.005)-1.644(+.006,-.006)
Hardness: 7-7.5
Chemical Comp: (NaCa)(LI,MgFe,Al)9B3Si6(O,OH)31
Density: 3.06 (.05, +.15)
Crystal Group: Hexagonal

The name Tourmaline comes from the Singhalese (Sri Lankan) words ‘tura mali’ –Gem with several colors some  have two or more colors,  some  even color-changing, and also a rare variety- the Cats-eye.
Sri Lanka produces a beautiful multi-colored tourmaline – a mix of red yellow and green which are more like color-changing. Multicolored gems are truly a gemological wonder, as they have a unique beauty of their own displaying different colors at different angles due to pleochroism.