Multicolor Tourmaline Identification Guide
How to identify multicolor (parti-colored) tourmaline by its color zoning, striated prisms, rounded-triangular cross-section, and pleochroism.
Read the full Multicolor Tourmaline encyclopedia entry →
What Multicolor Tourmaline Looks Like
Multicolor tourmaline is elbaite (the lithium-rich tourmaline species) that displays two or more distinct colors in a single crystal or cut stone. Zoning may run along the length of the prism or across it.
- Color: combinations such as green/pink, blue/green, pink/clear, or three-plus zones; watermelon (green rind, pink core) is a famous variety
- Luster: vitreous
- Transparency: transparent to translucent
- Habit: elongated three-sided (trigonal) prisms with a rounded-triangular cross-section and heavy lengthwise striations
- Terminations: crystals are often differently shaped at each end (hemimorphic)
Step-by-Step Field ID Checklist
- Look for parallel striations (grooves) running the length of the prism — a tourmaline hallmark.
- Check the cross-section: tourmaline is rounded-triangular, not square or hexagonal.
- Note distinct color zones with sharp or gradational boundaries.
- Rotate the stone to observe strong pleochroism (color changes with viewing angle).
- Test hardness — it scratches quartz (7-7.5).
Key Diagnostic Tests
- Mohs hardness: 7-7.5.
- Streak: white.
- Cleavage/fracture: essentially no cleavage; conchoidal to uneven fracture.
- Optics: doubly refractive with strong dichroism/pleochroism — a powerful diagnostic.
- Density: SG ~3.0-3.1.
- Pyroelectric/piezoelectric: tourmaline develops a static charge when heated or rubbed and attracts dust/ash.
Common Look-Alikes and How to Tell Them Apart
- Bi-color tourmaline: simply a two-color version of the same elbaite; "multicolor" implies three or more zones. Same tests apply.
- Ametrine (citrine/amethyst quartz): also zoned, but quartz lacks the rounded-triangular cross-section and lengthwise striations, and shows weaker pleochroism.
- Fluorite: softer (Mohs 4) with perfect octahedral cleavage — fails the scratch test against quartz.
- Color-zoned sapphire: much harder (Mohs 9) and far denser.
- Glass/assembled imitations: look for bubbles, lack of striations, and weak or absent pleochroism.
Where It Is Found
Multicolor elbaite comes from granite pegmatites. Major sources include Brazil (Minas Gerais), Afghanistan, Pakistan, Nigeria, Madagascar, Mozambique, and California/Maine in the United States.
Frequently asked questions
How can you tell if it's real multicolor tourmaline?
Real tourmaline shows a rounded-triangular cross-section, strong lengthwise striations, a hardness of 7-7.5, and very strong pleochroism (the color shifts as you rotate it). Glass and most imitations lack the striations and the strong pleochroism.
What is parti-colored tourmaline?
Parti-colored or multicolor tourmaline is a single elbaite crystal showing two or more distinct color zones, such as the green-and-pink watermelon variety, caused by changes in trace chemistry during growth.
What does multicolor tourmaline look like?
It is a glassy, elongated three-sided prism (or faceted stone) with heavy lengthwise grooves and two or more sharply or gradually zoned colors like pink, green, blue, or clear.
Multicolor tourmaline vs ametrine — how are they different?
Both are zoned, but ametrine is quartz lacking tourmaline's striated rounded-triangular prisms and showing only weak pleochroism, while tourmaline shows strong pleochroism and distinctive crystal form.