Description of Vivid Green Tsavorite Garnet (Tanzania)

1. Mineralogy & Chemistry
   

   • Tsavorite is a variety of grossular garnet, with chemical formula Ca3Al2Si3O12.

   • Its vibrant green color comes primarily from trace amounts of vanadium, plus some chromium.

3. Color & Appearance
   

   • “Vivid green” tsavorite from Tanzania often exhibits a lively, saturated green — sometimes with a slight bluish or yellowish undertone.

   • Color range is from light/mint green all the way to deep forest green.

   • Under UV light, tsavorite from Tanzania (especially from Merelani Hills) can show pink-red and yellow fluorescence, which is unusual among garnets.

5. Origin & Geology
   

   • First discovered in 1967 by Campbell Bridges in northeastern Tanzania (Lemshuko / Komolo area).

   • Major mining areas include Merelani Hills (where tsavorite is often found in or near tanzanite-bearing rocks) as well as Karo Pit in Merelani.

   • The crystals often grow on a dark matrix (graphite or quartz), which gives a nice contrast to the green color.

7. Physical & Optical Properties
   

   • Hardness: ~7.0–7.5 on the Mohs scale, making it reasonably durable for jewelry.

   • Refractive index: around 1.740, and because it’s isometric (cubic), tsavorite is singly refractive (no birefringence).

   • Dispersion (fire): moderate (~0.028), giving it some sparkle.

   • Specific gravity: ~ 3.60–3.68.

9. Clarity & Crystal Habit
   

   • High-quality tsavorites are often quite clean (eye-clean), though inclusions are not uncommon.

   • In nature, tsavorite crystals from Tanzania often form in “potato”-like nodules rather than perfect euhedral shapes.

   • However, well-formed crystals have been documented, especially in the Karo pit, showing complex crystal habits.

11. Rarity & Value
    

    • Tsavorite is relatively rare, especially in high-saturation “vivid green” tones.

    • Large, clean stones over several carats (especially vivid green) are quite valuable.

    • Importantly: tsavorite is typically untreated, which is a strong plus for many gem buyers.

13. Care
    

    • Because it’s fairly hard, tsavorite is suitable for many types of jewelry.

    • Cleaning: warm soapy water is generally safe; avoid steam cleaning if there are internal fluid inclusions.

Why it’s special:

• The vivid green hue rivals that of emeralds but without the common treatments or high fracture issues of emeralds.

• The Tanzanian source (especially Merelani) produces tsavorite with very good clarity and color — including rare well-formed crystals that are prized by collectors.

• Fluorescence under UV (in some Tanzanian tsavorites) adds an extra dimension of beauty and scientific interest.