Sodalite is a fascinating gemstone known for its vibrant blue hues and unique tenebrescence, the ability to change color under UV light. In recent years, high-quality sodalite (also called hackmanite) has been sourced from Myanmar and Afghanistan. If you are a gem collector, jeweler, or enthusiast looking to understand the differences between these two sources, this comprehensive comparison will help you make an informed choice.
1. General Characteristics
Tenebrescence: Both Myanmar and Afghan sodalite exhibit tenebrescence, allowing them to change color when exposed to UV light.
Transparency: Afghan sodalite is typically more transparent, whereas Burmese sodalite tends to have more inclusions.
2. Transparency & Clarity
Afghan Sodalite: Cleaner, with fewer inclusions and higher transparency.
Burmese Sodalite: More included, often with visible fractures and foreign material.
3. Color and Tenebrescence
Burmese Sodalite: Usually has a deeper, richer purple or violet color.
Afghan Sodalite: Ranges from very light violet to medium purple.
Tenebrescence: Afghan sodalite generally has a stronger tenebrescence effect than Burmese sodalite.
4. UV Fluorescence and Phosphorescence
Afghan Sodalite: Strong yellow to orange fluorescence under long-wave UV, moderate to strong white fluorescence under short-wave UV.
Burmese Sodalite: Weaker fluorescence, typically greenish-yellow in fractures.
Phosphorescence: Afghan sodalite shows stronger phosphorescence than Burmese sodalite.
5. Refractive Index & Specific Gravity
Afghan Sodalite: Refractive index of 1.45 - 1.48.
Burmese Sodalite: Refractive index of 1.47 - 1.48.
Specific Gravity: Burmese sodalite sometimes has a higher SG (up to 2.44) due to the presence of nepheline inclusions.
6. Spectroscopy & Chemistry
Both types contain traces of sulfur, which contribute to tenebrescence.
Afghan sodalite exhibits additional spectral features in UV-Vis-NIR spectra, such as peaks at 410-412 nm, 277 nm, and 313 nm, which are not found in Burmese sodalite.
7. Treatment
Afghan Sodalite: Often oiled to enhance clarity.
Burmese Sodalite: May also undergo oiling, especially after cutting.
Conclusion: Which One Should You Choose?
If you want a gemstone with strong tenebrescence, Afghan hackmanite is the better choice.
If you prefer a deep, rich purple or violet color, Burmese sodalite is ideal.
For higher transparency and fewer inclusions, Afghan sodalite is superior.
If you appreciate UV fluorescence and phosphorescence, Afghan sodalite offers stronger effects.
Final Thoughts
Both Myanmar and Afghan sodalite have their own unique appeal. Whether you’re a gem enthusiast, collector, or jeweler, understanding these differences can help you make a more informed decision. For investment or aesthetic purposes, consider your preference for tenebrescence, clarity, and fluorescence when choosing between these two beautiful varieties of sodalite.
Title: Sodalite from Myanmar vs. Afghanistan – Differences, Color, & Value
Meta Description: Discover the key differences between Burmese and Afghan sodalite, including color, tenebrescence, transparency, UV fluorescence, and treatment.
No comments:
Post a Comment