Tourmaline

About

Tourmaline is a versatile gemstone that comes in a wide range of colours, including pink, green, blue, black, and even multicoloured varieties. This diversity is due to its complex boron silicate composition with varying trace elements. Major sources include Brazil, Afghanistan, Madagascar, and Nigeria.

Birthstones & Anniversaries

Tourmaline is an alternate birthstone for October and is traditionally given for the 8th anniversary, symbolising protection, love, and creativity.

Crystal Healing Energy

The overarching theme of tourmaline is protection and balance. Each colour carries its unique energy: black tourmaline is grounding, pink promotes love, green encourages growth, and blue inspires calm. Tourmaline is believed to shield against negative energy, balance the mind and emotions, and encourage self-confidence and focus. Multicoloured varieties are often associated with aligning the chakras and encouraging harmony.

Facts

Pleochroism: Tourmaline often exhibits pleochroism, meaning its colours shift when viewed from different angles, adding to its dynamic beauty.

Multicoloured Varieties: Watermelon tourmaline, with pink and green bands, is one of the most popular and unique varieties.

Electric Properties: Tourmaline is pyroelectric and piezoelectric, meaning it can generate an electric charge when heated or compressed.

Durable for Jewellery: With a Mohs hardness of 7 to 7.5, tourmaline is suitable for most jewellery types.

Geological Formation: Tourmaline forms in granite pegmatites and is often found alongside quartz and feldspar.

Science

Mineral: Tourmaline
Crystal System: Trigonal
Chemistry: (Na,Ca)(Li,Mg,Al,Fe²⁺,Mn²⁺)₃(Al,Cr,Fe³⁺,V)₆(BO₃)₃(Si₆O₁₈)(OH,F)₄
Colour: Black, pink, green, blue, yellow, brown, multicoloured
Refractive Index: 1.614 to 1.666
Birefringence: 0.014 to 0.022
Specific Gravity: 2.82 to 3.32
Mohs Hardness: 7 to 7.5

Treatments

Tourmaline may be heat-treated to enhance colour, particularly in pink and green varieties. Some stones are also irradiated to deepen their hues, though these treatments are stable and widely accepted in the market.

Synthetics

Synthetic tourmaline is rare but has been produced for scientific purposes.

Imitations

Glass, synthetic spinel, and quartz are often used as imitations for tourmaline. These materials may replicate its colour but lack its characteristic pleochroism (colour changes when viewed from different angles).

similar materials

Quartz: Certain varieties, like green aventurine or pink rose quartz, may resemble tourmaline but lack its pleochroism and structure.
Spinel: Found in similar hues, spinel is harder and has a different crystal structure.
Andalusite: A pleochroic gemstone that can sometimes mimic the multicoloured effect of tourmaline but differs in composition.