Tanzanite is a highly prized gemstone known for its stunning violet-blue hue and rarity, found exclusively in a small region of Tanzania. Due to its delicate nature and the high value placed on its appearance, many tanzanite stones undergo various treatments to enhance their color, clarity, and overall appeal. Understanding these treatments is essential for buyers, collectors, and enthusiasts alike, as it helps in making informed decisions and ensures transparency in gemstone transactions. In this article, we’ll explore the common treatments employed on tanzanite, their purpose, and what to look for when purchasing this beautiful gemstone.
What Are Common Tanzanite Treatments?
Most tanzanite stones on the market have undergone some form of treatment to optimize their appearance. Unlike natural enhancements, these treatments are generally considered stable and widely accepted within the jewelry industry. However, transparency from sellers about any treatments applied is vital for ethical purchasing. Below are the most common treatments used on tanzanite and their implications.
Heat Treatment
Heat treatment is the most prevalent and accepted enhancement method for tanzanite. It involves exposing the gemstone to high temperatures to improve its color and clarity. This process typically occurs during the initial cutting and polishing stage and is considered stable over time.
- Purpose: To enhance the deep violet-blue hue, reduce brownish tones, and improve overall color saturation.
- Process: The gemstone is heated at temperatures ranging from 500°C to 700°C in a controlled environment. This alters the crystal structure and removes unwanted color zoning or brownish hues.
- Result: Most tanzanite on the market is heat-treated to achieve its vibrant, desirable color. Properly treated stones retain their color permanently and are considered stable for jewelry wear.
- Note: Heat treatment does not significantly affect a tanzanite’s durability or value when disclosed and properly done.
Potential Other Treatments
While heat treatment is the most common, some other treatments may be used, either to improve appearance or alter the gemstone’s characteristics. These are less common and sometimes less stable or accepted.
Oiling or Resin Infusion
This technique involves filling surface-reaching fractures or inclusions with a resin or oil to improve clarity and stability. However, it is rarely applied to tanzanite due to its relatively high stability after heat treatment.
Color Coating
Some lower-quality tanzanite might be coated with a thin layer of color-enhancing material to improve appearance. This treatment is generally considered less stable, as coatings can wear off over time.
Impregnation or Dyes
While uncommon for tanzanite, some stones could be impregnated with dyes to alter or deepen their color. Such treatments are typically disclosed but are less favored because they can degrade with exposure to heat or chemicals.
How to Identify Tanzanite Treatments
Identifying whether a tanzanite has undergone treatments requires expertise and proper equipment. Here are some indicators and methods used by gemologists:
- Certification: Reputable gem labs provide certificates indicating whether a stone has been heat-treated or subjected to other enhancements.
- Visual Inspection: Under magnification, a gemologist can detect signs of treatments, such as surface coatings or resin infillings.
- Color Consistency: Uniform, vibrant coloration across the stone often suggests heat treatment, while uneven color may indicate other treatments or natural origin.
- Testing Equipment: Advanced tools like spectrometers can analyze the gemstone’s internal structure and confirm treatments.
Importance of Transparency and Ethical Buying
As with all gemstones, honesty about treatments is essential for maintaining trust and value. Reputable dealers disclose any treatments applied to tanzanite and provide certification from recognized laboratories. Buyers should always request certification and buy from reputable sources to ensure they receive a genuine, ethically treated stone.
Understanding the treatments applied to tanzanite helps in assessing its value, durability, and appearance longevity. Properly treated tanzanite, especially heat-treated stones, are widely accepted and offer excellent beauty at a reasonable price point. Always prioritize transparency and certification to make informed and satisfying jewelry purchases.
Summary of Key Points
- Most tanzanite on the market is subjected to heat treatment to enhance color and clarity.
- Heat treatment is stable, widely accepted, and considered safe when disclosed.
- Other treatments, such as coatings or dyeing, are less common and may be less stable or transparent.
- Professional certification and expert evaluation are essential for identifying treatments accurately.
- Always buy from reputable sources that provide full disclosure of any treatments applied to the gemstone.
