Introduction to the world of tourmalines

I recently took the course “Introduction to the World of Tourmalines” offered by the Swiss Gemmological Institute, and I discovered just how fascinating these gemstones are. Tourmaline is a complex borosilicate mineral, known for its wide range of colors and its trichroism, which sometimes allows a single crystal to show multiple shades.

From rough stone to polished gem, the journey of a tourmaline is impressive. After extraction, gemologists assess the stone’s color, clarity, and structure before cutting and polishing it to reveal its full brilliance and transparency. Tourmalines form in boron-rich igneous or metamorphic rocks, and their colors are directly influenced by the elements present during their formation.

Tourmalines are mainly sourced from Brazil, Madagascar, Sri Lanka, Afghanistan, and Mozambique, with each region producing stones with unique characteristics. Valued since ancient times for their beauty and supposed protective properties, tourmalines gained particular popularity in the 19th century with the rise of colored jewelry.

Tourmalines come in almost every color. Some varieties have specific trade names: rubellite for red to pink, indicolite for blue, verdelite for green, and the very rare Paraíba for neon blue-green. Scientific analysis of these stones involves microscope observation, spectroscopy, and polarimetry, allowing gemologists to understand their composition and identify natural stones.