Tourmaline’s colors have many different causes. It’s generally agreed that traces of iron, and possibly titanium, induce green and blue colors. Manganese produces reds and pinks, and possibly yellows. Some pink and yellow tourmalines might owe their hues to color centers caused by radiation, which can be natural or laboratory-induced.Tourmaline Description Tourmaline History and Lore
Birthstones & AnniversariesTourmaline is a birthstone for October, along with opal. Tourmaline is also the gem of the eighth anniversary.
Francisco Spinoza’s expedition discovers “Brazilian emerald”: the first recorded green tourmaline crystal.
Tourmaline becomes electrically charged when heated. Also when squeezed: it’s piezoelectric too.
Brazilian source famous for vivid blue to green tourmalines colored by copper.
1.624 to 1.644
0.018 to 0.040
3.06 (+0.20, -0.06)
7 to 7.5
Where It's Found
There are a number of processes used to alter the color, apparent clarity, or improve the durability of gems.Learn More
Some gemstones have synthetic counterparts that have essentially the same chemical, physical, and optical properties, but are grown by man in a laboratory.Learn More
Any gem can be imitated—sometimes by manmade materials or by natural materials chosen by man to impersonate a particular gem.Learn More
Why We Love This Gemstone
Tourmaline crystallizes in the trigonal system; no other common mineral has three-sided prisms.
Watermelon tourmaline is green on the outside and a delicious pink on the inside.
Liddicoatite tourmaline was named for beloved former GIA President Richard T. Liddicoat.
Tourmaline’s varieties have a wide range of quality factors considerations.
Tourmaline's rainbow colors have a wide range of color intensity and tone.
Pink to red tourmaline often has more visible inclusions than green to blue varieties.
Tourmaline crystals are often long, leading cutters to cut slender finished stones.
Tourmalines come in all shapes and sizes. The value change for size varies with the variety.
Tourmaline Quality Factors: The Comprehensive Guide
Explore sources, gemological research, and the role of gems in history.
Copper-Bearing (Paraíba-Type) Tourmaline from MozambiqueBrendan M. Laurs, J. C. (Hanco) Zwaan, Christopher M. Breeding, William B. (Skip) Simmons, Donna Beaton, Kenneth F. Rijsdijk, Riccardo Befi, and Alexander U. Falster , May 5, 2008 Read Article
“Paraíba”-Type Copper-Bearing Tourmaline from Brazil, Nigeria, and Mozambique: ...Ahmadjan Abduriyim, et al. Read Article
Paraiba Tourmaline: “Electric Blue Brilliance Burnt Into Our Minds”
Collector’s Guide to the Tourmaline Group
Robert J. Lauf
Tourmaline: A Gemstone Spectrum
Brian C. Cook