Mint Tourmaline Identification Guide
How to identify Mint Tourmaline, a pastel green elbaite, by its striated prisms, pleochroism, double refraction, and hardness.
Read the full Mint Tourmaline encyclopedia entry →
What Mint Tourmaline Looks Like
Mint Tourmaline is a pale, fresh green elbaite tourmaline with a delicate pastel "mint" tone (sometimes with a faint blue or yellow cast). It is essentially the same as mint green tourmaline, prized for its clean, light color.
- Color: Light pastel green, mint, sometimes bluish-mint.
- Luster: Vitreous.
- Transparency: Transparent to translucent.
- Habit/form: Long striated prisms with rounded-triangular cross-section.
Step-by-Step Field ID Checklist
- Examine crystal form (rough): Long prisms, rounded triangular cross-section, strong lengthwise striations = tourmaline.
- Test pleochroism: Rotate the stone; tourmaline shows two clearly different shades of green.
- Check for doubling: A loupe reveals doubled facet edges (double refraction).
- Look for tube inclusions: Thread-like hollow tubes parallel to length are typical.
- Confirm hardness and density (below).
Key Diagnostic Tests
- Mohs hardness: ~7–7.5.
- Streak: White.
- Cleavage: Indistinct/poor; uneven to conchoidal fracture.
- Density: ~3.0–3.1 g/cm3.
- Optics: Doubly refractive, strong pleochroism, RI ~1.62–1.64.
- Acid: No reaction.
Common Look-Alikes and How to Tell Them Apart
- Mint/green grossular garnet: Singly refractive (no doubling or pleochroism), heavier (~3.5–3.7); tourmaline doubles and is pleochroic.
- Peridot: More olive-yellow, softer, density ~3.3, strong doubling but different color; tourmaline is more even mint.
- Green beryl/aquamarine: Six-sided flat-faced prisms; weaker pleochroism than tourmaline.
- Chrome diopside: Softer (5.5–6.5), darker green.
- Green glass: Gas bubbles, single refraction, softer and less dense.
Where It Is Found
Mint elbaite tourmaline comes from granite pegmatites in Brazil, Afghanistan/Pakistan, Nigeria, Mozambique, Madagascar, and the U.S. (Maine, California).
Frequently asked questions
How can you tell if Mint Tourmaline is real?
Genuine mint tourmaline shows strong pleochroism, double refraction (doubled facet edges via loupe), hardness ~7–7.5, and density ~3.0–3.1, with striated prismatic rough. Bubbles and single refraction indicate glass.
What is the difference between mint tourmaline and mint green tourmaline?
They are the same thing — both are pale, pastel green elbaite tourmaline. The names are used interchangeably in the trade.
Mint tourmaline vs mint garnet — how do you tell them apart?
Mint tourmaline is doubly refractive and pleochroic with lower density (~3.0–3.1); mint garnet is singly refractive, non-pleochroic, and denser (~3.5–3.7).
What does mint tourmaline look like?
It is a clean, pale pastel-green transparent gem cut from striated prismatic crystals, with a glassy luster and a soft minty tone.