The group
No other gem family does this. A single tourmaline crystal can be pink at one end and green at the other, or pink in the middle with a green rind — the watermelon pattern. The chemistry of the growing crystal changed while it grew, and the crystal recorded it.
The trade uses colour names rather than species names: rubellite for red and pink, indicolite for blue, verdelite for green, achroite for colourless, schorl for black. Most of these are the species elbaite, except schorl, which is a separate iron species. Paraíba is the exception that is defined by a chromophore rather than a colour: copper.
The honest problem with tourmaline is treatment. Heating and irradiation are both routine, both change colour, and neither can be detected. The LMHC lists tourmaline among the materials whose colour origin cannot be determined, so no laboratory report will tell you. Anyone certain their tourmaline is untreated is guessing.
Tourmaline is also strongly pleochroic, usually darker down the length of the crystal than across it, which is why cutters orient the table across the c-axis and why a badly oriented stone looks flat.
Every tourmaline compared
The whole group side by side. Where the constants overlap, the species cannot be named from a refractometer alone — which is exactly why the trade names mislead.
| Variety | Species | Colour | Mohs | RI | SG | Guide price |
|---|---|---|---|---|---|---|
| Achroite | Elbaite (tourmaline supergroup) | colourless | 7–7.5 | 1.619–1.640 | 3.01–3.06 | $20–150/ct |
| Canary Tourmaline | Tourmaline supergroup (elbaite) | yellow | 7–7.5 | 1.619–1.640 | 3.05–3.10 | 80–500 USD/ct for clean saturated stones |
| Cat's Eye Tourmaline | Elbaite (tourmaline supergroup) | green | 7–7.5 | 1.619–1.644 | 3.01–3.11 | $50–600/ct |
| Chrome tourmaline | Dravite tourmaline | green | 7–7.5 | 1.620–1.640 | 3.01–3.11 | $200–1,500/ct |
| Dravite | Dravite (tourmaline supergroup) | orange | 7–7.5 | 1.610–1.640 | 3.03–3.15 | $10–200/ct |
| Fluor-buergerite | Tourmaline supergroup | black | 7 | 1.735–1.770 | 3.31 | Crystals 30–250 USD |
| Foitite | Tourmaline supergroup | violet | 7 | 1.630–1.655 | 3.17 | Specimens 30–300 USD |
| Indicolite | Elbaite tourmaline | teal | 7–7.5 | 1.620–1.640 | 3.01–3.11 | $50–1,500/ct |
| Liddicoatite | Liddicoatite (tourmaline supergroup) | pink | 7–7.5 | 1.621–1.641 | 3.02–3.06 | Slices $20–500 per piece by pattern |
| Paraíba tourmaline | Elbaite tourmaline | teal | 7–7.5 | 1.620–1.640 | 3.01–3.11 | $1,000–50,000/ct |
| Povondraite | Tourmaline supergroup | black | 7 | 1.77–1.83 | 3.26 | Specimens 40–400 USD |
| Rossmanite | Tourmaline supergroup | pink | 7–7.5 | 1.624–1.645 | 3.00–3.06 | Faceted stones 50–250 USD/ct |
| Rubellite | Elbaite tourmaline | red | 7–7.5 | 1.620–1.640 | 3.01–3.11 | $50–2,000/ct |
| Schorl | Schorl tourmaline | black | 7–7.5 | 1.635–1.675 | 3.10–3.25 | $0.20–5/ct |
| Schorlomite | Garnet group | black | 7–7.5 | 1.940–1.980 | 3.77–3.93 | Beads and cabochons 5–40 USD |
| Tourmalinated Quartz | Quartz with schorl inclusions | colourless | 7 | 1.544–1.553 | 2.65 | $2–30/ct |
| Tourmaline (Elbaite) | Elbaite (tourmaline supergroup) | green | 7–7.5 | 1.619–1.644 | 3.01–3.11 | $20–500/ct for common colours |
| Uvite | Uvite (tourmaline supergroup) | green | 7–7.5 | 1.619–1.639 | 3.03–3.10 | $20–200/ct |
| Verdelite | Elbaite (tourmaline supergroup) | green | 7–7.5 | 1.619–1.644 | 3.01–3.11 | $30–400/ct |
| Watermelon tourmaline | Elbaite tourmaline | pink | 7–7.5 | 1.620–1.640 | 3.01–3.11 | $30–600/ct |
Questions
Is tourmaline treated?
Usually, and it cannot be proven either way. Heating and irradiation are both common in tourmaline and both are undetectable, so the honest position is to assume the colour may have been modified and to price accordingly.
What makes Paraíba tourmaline so expensive?
Copper as the chromophore, which produces a neon blue-green found in no other tourmaline, and extreme scarcity — the original Brazilian deposit is largely worked out. Fine stones reach tens of thousands of dollars per carat.
What is the difference between rubellite and pink tourmaline?
Rubellite holds its red under warm incandescent light; pink tourmaline browns out under the same bulb. The boundary is a trade judgement, not a laboratory determination, and the price gap across it is several times.
Is tourmaline durable?
Reasonably. At 7 to 7.5 with only indistinct cleavage it wears well, though heavily included rubellite can be fragile and should be set protectively.
Looking for tourmaline?
Tell us which variety, what size and what it is for. We source it, photograph it and quote it, with the locality named.
Ask about tourmaline