Gemstones
Tourmaline: One Mineral, Every Colour
Tourmaline occurs in more colours than almost any other gem species, including the copper-bearing Paraiba variety that commands exceptional prices.
A family of colours
Tourmaline's complex chemistry allows for an unusually wide colour range — green, pink, red (rubellite), blue, and bi-colour or watermelon stones showing two colours in one crystal.
Paraiba tourmaline
Paraiba tourmaline, coloured by trace copper, shows an intense neon blue-green unmatched by other gems and is among the most valuable coloured stones per carat; origin reports from major labs are standard for high-value pieces.
Treatment and durability
Many tourmalines are untreated; some are heat-treated to improve colour, which is generally stable and disclosed. At 7–7.5 Mohs hardness, tourmaline wears well in most jewelry.
Buyer checklist
- ✓ Ask for a lab report confirming Paraiba origin on high-value stones
- ✓ Confirm whether heat treatment was applied
- ✓ Check clarity, since included tourmaline can affect brilliance
Verification tools & references
Every Riakoob piece arrives certified, insured and covered by our 12-month value promise.
Browse the collection