Gem of the Day: Tourmaline – The Rainbow Stone

Tourmaline, often referred to as the "Rainbow Stone," owes its name to the Sinhalese word "turmali," which means "a mixed-colored stone." Known for its incredible spectrum of colors, this gemstone is also called "Electric Stone" due to its unique piezoelectric and pyroelectric properties. These properties allow one end of the tourmaline’s columnar structure to develop a positive charge and the other end a negative charge, producing electricity when heated or rubbed. Thanks to its ability to release negative ions and electric currents, tourmaline is often considered a mineral that promotes health and well-being.

Origins and Chemistry

  • Primary Sources: Brazil, the United States, Madagascar, Sri Lanka, Mozambique, Namibia, and Russia
  • Chemical Formula: Na(Mg,Fe,Mn,Li,Al)3Al6[Si6O18][BO3]3(OH,F)4

 

Purification Methods

While most purification methods are suitable for tourmaline, avoid using sunlight purification for lighter-colored varieties, as prolonged exposure can damage the stone. Black tourmaline, however, can safely undergo sunlight purification.


Precautions for Care

To maintain its brilliance and longevity, handle tourmaline with care:

  • Avoid Prolonged Sunlight Exposure: Excessive heat can cause discoloration.
  • Keep Away from Chemicals: Perfumes, cosmetics, and detergents may corrode the surface and dull its luster.
  • Temperature Sensitivity: Avoid cleaning with hot water for extended periods, as high temperatures can alter the stone's color.

 

How to Identify Authentic Tourmaline

  1. Pleochroism: Observe the stone from different angles; genuine tourmaline will display two distinct colors.
  2. Pyroelectric and Piezoelectric Properties: Rub the stone gently to create static electricity, allowing it to attract dust, hair, or paper particles.
  3. High Double Refraction: Use a magnifying glass to observe the girdle lines through the table; genuine stones will show noticeable doubling.
  4. Inclusions: Natural tourmaline often contains tubular inclusions or gas-liquid inclusions, which add to its uniqueness.


Tourmaline’s dazzling colors and fascinating properties make it a cherished gemstone in both jewelry design and holistic practices. With proper care, it can remain a vibrant, meaningful addition to your collection for years to come.

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