Tsavorite Garnet Identification Guide

What Tsavorite Garnet Looks Like

Tsavorite is the vivid green, vanadium- and chromium-colored variety of grossular garnet (a calcium aluminium silicate). It is prized for a bright, slightly yellowish to bluish green and excellent brilliance, often rivaling emerald but with greater fire and durability of color.

• Color: Bright green to deep forest green, sometimes with a yellowish secondary hue.
• Luster: Vitreous to subadamantine; high brilliance.
• Transparency: Transparent.
• Crystal habit: Isometric (cubic) — typically dodecahedral or trapezohedral crystals, though most gem material is faceted from rough grains.

Field-ID Checklist

1. Note the bright, lively green with strong sparkle.
2. Check for high brilliance/fire — garnets return a lot of light.
3. Test hardness — 7 to 7.5; scratches glass.
4. Look for crystal form — well-formed garnets are rounded dodecahedra.
5. Check optics — garnet is singly refractive (no doubling of back facets), unlike emerald.
6. Inspect inclusions — tsavorite often has fewer, more rounded inclusions than emerald's busy jardin.

Key Diagnostic Tests

• Mohs hardness: 7–7.5. Scratches glass; tougher than emerald.
• Streak: White.
• Cleavage/fracture: No cleavage; conchoidal to uneven fracture.
• Crystal system: Isometric (cubic) — therefore singly refractive (isotropic), a key separator from doubly refractive emerald and tourmaline.
• Refractive index: High, ~1.73–1.75, with no birefringence; appears red through a Chelsea filter in chromium-rich stones.
• Density: ~3.6–3.7, distinctly higher than beryl.

Common Look-Alikes

• Emerald (green beryl): Doubly refractive, lower RI (~1.57–1.60), lower density, and usually heavily included; tsavorite is singly refractive, denser, and brighter.
• Green tourmaline: Doubly refractive with strong pleochroism; tsavorite shows no pleochroism.
• Chrome diopside: Softer (Mohs 5.5–6) and doubly refractive.
• Demantoid garnet: Another green garnet (andradite) but with much higher dispersion (fire) and distinctive horsetail inclusions; tsavorite is grossular with less dispersion.
• Peridot: Yellowish-green, doubly refractive with strong doubling, and lower RI.
• Green glass: Singly refractive too, but softer, with bubbles and lower density.

Where It's Found

Tsavorite was discovered in the late 1960s near the Kenya–Tanzania border and named after Tsavo National Park. Principal sources are Tanzania (Merelani and Lemshuko areas) and Kenya, with additional finds in Madagascar and elsewhere. It forms in metamorphosed calcareous and graphitic gneisses where vanadium and chromium impart the green color.