Gem Minerals
Tourmaline
What it is
The most chemically complex silicate mineral, with a formula that can incorporate nearly every element. This chemical flexibility produces an unmatched range of colors — sometimes multiple colors in a single crystal (watermelon tourmaline). Tourmaline is also pyroelectric and piezoelectric, generating voltage when heated or squeezed.
How it forms
Crystallizes in granite pegmatites and metamorphic rocks where boron-rich fluids are present. The boron is essential — no boron, no tourmaline. Color zoning occurs when the fluid chemistry changes during crystal growth.
Complex borosilicate — (Na,Ca)(Mg,Fe,Li,Al)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄
Specimens
6 stones
Black Tourmaline
Protection · Root
Final 'soup' of a magma chamber.
Green Tourmaline
Healing · Heart
High lithium content in pegmatites.
Indicolite
Intuition · Crown
Iron-rich tourmaline in pegmatites.
Pink Tourmaline
Love · Heart
Lithium and manganese inclusions.
Tourmaline
Protection · Crown
Final 'sink' for elements in magma.
Watermelon Tourmaline
Love · Heart
Zoning from pink (Mn) to green (Fe).