Particolored Tourmaline Identification Guide

What Particolored Tourmaline Looks Like

Particolored tourmaline (parti-colored, multicolor) is elbaite tourmaline that shows two or more distinct colors within a single crystal. The colors can be zoned lengthwise along the crystal (e.g., green grading to pink) or concentrically across the cross-section. The most famous variant, "watermelon" tourmaline, has a pink core and green rind. Crystals are transparent to translucent with a glassy luster and the classic rounded-triangular prismatic form with strong vertical striations.

• Color: two+ colors - green/pink, blue/green, colorless/pink, etc.
• Transparency: transparent to translucent
• Luster: vitreous
• Habit: striated prisms, rounded triangular cross-section, color zoning

Step-by-Step Field ID Checklist

1. Confirm multiple colors in one crystal - the defining trait.
2. Look at the cross-section. Concentric color zones (like watermelon) point to tourmaline.
3. Find the striations running the length of the prism and the rounded triangular outline.
4. Hardness test. Mohs 7-7.5; scratches glass.
5. Check pleochroism - color shifts when rotated.
6. Inspect for cleavage. Tourmaline has essentially no good cleavage (separates it from fluorite/topaz).

Key Diagnostic Tests

• Mohs hardness: 7-7.5.
• Streak: white.
• Cleavage: poor/indistinct; fracture uneven to conchoidal.
• Density: ~3.0-3.1 g/cm3.
• Optics: strongly pleochroic and doubly refractive.

Common Look-Alikes and How to Tell Them Apart

• Fluorite (multicolor): much softer (Mohs 4) with perfect octahedral cleavage; tourmaline is hard with no cleavage.
• Color-zoned quartz/ametrine: quartz has hexagonal prisms with horizontal striations and no triangular cross-section; tourmaline striations run lengthwise.
• Bi-color sapphire: far harder (9) and much denser (~4.0).
• Assembled/dyed imitations: color boundaries are sharp/glue-line straight; natural zoning is gradational and follows crystal growth.
• Glass doublets: singly refractive, may show bubbles, lack pleochroism.

Where It Is Found

Particolored tourmaline forms in granitic pegmatites. Major sources include Brazil (Minas Gerais), Afghanistan and Pakistan, Nigeria, Madagascar, Mozambique, and the United States (notably Maine and California), where changing fluid chemistry during crystal growth produced the color zoning.