Tanzanite, with its mesmerizing blue-violet hues, has captivated the hearts of gemstone enthusiasts and jewelry collectors worldwide. Discovered in Tanzania in the 1960s, this rare gemstone has garnered immense popularity. However, its scarcity and allure have also made it a target for counterfeiters and dishonest sellers. To safeguard your investment and appreciation for the beauty of real tanzanite, it is crucial to learn how to tell real tanzanite from fake. In this comprehensive guide, we will explore the key factors that distinguish genuine tanzanite from imitations and provide you with the knowledge to make informed purchases.
Understanding the Rarity of Tanzanite
Before delving into the techniques for identifying real tanzanite, it is essential to grasp the rarity and value of this gemstone. Tanzanite is unique because it is found in only one location on Earth – the Merelani Hills of Tanzania. This exclusivity makes tanzanite rarer than diamonds and contributes significantly to its allure and price.
Due to its scarcity, tanzanite is highly sought after by collectors and investors. This intense demand has driven up prices and made it a prime target for counterfeiters. Hence, being able to distinguish genuine tanzanite from fake is of paramount importance for anyone considering acquiring this gem.
The Physical Properties of Tanzanite
To tell real tanzanite from fake, one must first understand the physical properties that set this gem apart. Genuine tanzanite possesses a set of unique characteristics that counterfeit stones often struggle to replicate accurately.
Color Variations in Tanzanite
The color of tanzanite is its most distinctive feature. Authentic tanzanite exhibits a striking blue-violet or violet-blue coloration, often described as “trichroic” because it can display different hues when viewed from different angles. The most coveted tanzanite shades range from a rich royal blue to a deep violet, with a vivid saturation that is hard to replicate. Fake tanzanite stones often lack the depth and intensity of color found in the genuine gem.
Trichroism in Real Tanzanite
As mentioned earlier, trichroism is a key feature of genuine tanzanite. When examining a tanzanite gemstone, observe how its color changes when viewed from different angles. Genuine tanzanite will display a range of blue and violet hues, while fake stones may appear more uniform in color.
Pleochroism in Tanzanite
Another important optical property is pleochroism, which refers to the ability of a gemstone to display different colors when viewed along different crystallographic axes. In the case of tanzanite, it typically shows blue, violet, and sometimes burgundy colors when observed from different angles. This phenomenon is a strong indicator of a real tanzanite gem.
Identifying Real Tanzanite through Transparency
The transparency of a gemstone is another essential factor in distinguishing real tanzanite from fake imitations. Tanzanite is known for its high transparency, allowing light to pass through and create stunning plays of color within the gem. To tell real tanzanite from fake, consider the following aspects:
Clarity and Inclusions
Genuine tanzanite often contains characteristic inclusions, which are tiny internal flaws or mineral traces. These inclusions, sometimes referred to as “tanzanite silk,” are fine, needle-like structures that can be seen under magnification. They are a natural feature of tanzanite and can help identify real stones. Fake tanzanite, on the other hand, may lack such inclusions or display artificial ones that do not resemble tanzanite silk.
Dispersion of Light
Tanzanite’s high transparency results in excellent light dispersion, producing flashes of color as light interacts with the internal structure of the gem. When examining a tanzanite stone, look for these flashes of color, known as “fire,” especially under different lighting conditions. Genuine tanzanite will exhibit impressive fire, while fake stones may appear dull or lack this captivating play of colors.
Double Refraction
Another optical property that can help tell real tanzanite from fake is double refraction. Tanzanite, like many gemstones, exhibits double refraction, meaning that it can split a single ray of light into two distinct rays. When viewing a tanzanite gemstone through a gemological instrument called a dichroscope, you should observe this phenomenon. Fake tanzanite may not display double refraction or may do so less prominently.
Real Tanzanite’s Durability and Hardness
Tanzanite is a relatively durable gemstone, but it is not impervious to damage. To distinguish real tanzanite from fake, consider its hardness and resistance to common gemstone tests:
Hardness of Tanzanite
The hardness of a gemstone is measured on the Mohs scale, which ranges from 1 (softest) to 10 (hardest). Tanzanite falls within the range of 6.5 to 7 on the Mohs scale, which is moderately hard. While tanzanite can withstand normal wear and tear, it is not as hard as sapphire or diamond. Beware of fake tanzanite that is harder or softer than this range, as it may be an imitation.
Scratch Test
Conducting a scratch test using materials of known hardness, such as a steel file (hardness 6.5) or a quartz crystal (hardness 7), can help verify the authenticity of tanzanite. Genuine tanzanite should not be easily scratched by these materials. If the stone shows scratches or abrasions, it is likely a fake.
Real Tanzanite’s Origin and Certification
One of the most reliable ways to ensure you are purchasing real tanzanite is to verify its origin and obtain proper certification:
Ask for Documentation
When buying tanzanite, always request a certificate of authenticity from a reputable gemological laboratory. A certificate will provide detailed information about the gem, including its origin, cut, carat weight, color, and any treatments it may have undergone. Gemological laboratories such as the Gemological Institute of America (GIA) and the International Gemological Institute (IGI) are trusted authorities that can issue reliable certificates for tanzanite.
Verify the Origin
Tanzanite’s exclusive source is the Merelani Hills in Tanzania. If a seller claims that the tanzanite is from any other location, exercise caution, as it may be a fake or an imitation. Always check the gem’s origin against the information provided in its certification.
Tanzanite Treatments and Enhancements
It is common for tanzanite to undergo treatments to enhance its color and clarity. While these treatments are accepted within the gemstone industry, it is essential to be aware of them when trying to tell real tanzanite from fake:
Heat Treatment
The most common treatment for tanzanite is heat treatment, which is used to improve its color. Authentic tanzanite is often heated to temperatures of around 500-600 degrees Celsius to enhance the blue and violet hues. While heat-treated tanzanite is still considered genuine, it is crucial to disclose this treatment to potential buyers.
Coating and Dyeing
Fake tanzanite stones may undergo surface coatings or dyeing to imitate the vibrant colors of real tanzanite. These treatments can be detected by experienced gemologists or through specialized equipment. Always be wary of tanzanite that seems too perfect or has an unnaturally consistent color.
Testing Techniques for Real Tanzanite
In addition to visual inspection, there are specific testing techniques that can help you determine the authenticity of tanzanite:
Ultraviolet (UV) Light
Exposing tanzanite to UV light can reveal unique fluorescent properties. Genuine tanzanite often exhibits a moderate to strong blue fluorescence under UV light. While this test alone cannot confirm authenticity, it can provide valuable supporting evidence.
Conductivity Test
Tanzanite is a mineral that typically exhibits electrical conductivity. Gemological instruments that measure electrical conductivity can help distinguish real tanzanite from fake imitations. Be sure to consult a professional gemologist for accurate results.
Specific Gravity Measurement
Determining the specific gravity of a gemstone involves comparing its weight in air to its weight in water. Tanzanite has a specific gravity range of approximately 3.35 to 3.55. Deviations from this range may indicate that the stone is not genuine.
Gemological Refractometer
A refractometer measures the gem’s refractive index, which can be compared to known values for tanzanite. Tanzanite typically has a refractive index of 1.691 to 1.700. Significant deviations may suggest a fake gem.
Consulting a Professional Gemologist
While the techniques mentioned above can help you tell real tanzanite from fake, it is essential to remember that gemstone identification can be complex, and imitations are continually evolving. For the highest level of confidence, it is recommended to consult a professional gemologist when in doubt. These experts possess the knowledge, experience, and specialized equipment necessary to accurately identify real tanzanite.
Conclusion: Protecting Your Investment in Tanzanite
Tanzanite’s captivating beauty and rarity make it a cherished gemstone, but its desirability has also attracted counterfeiters and dishonest sellers. To safeguard your investment and appreciation for the genuine beauty of tanzanite, it is crucial to learn how to tell real tanzanite from fake. By understanding the gem’s physical properties, transparency, durability, origin, and common treatments, you can make informed purchases and ensure that you possess a genuine piece of this remarkable gemstone’s history.
Remember that while visual inspection and basic tests can provide valuable insights, consulting a professional gemologist and obtaining proper certification are the most reliable ways to verify the authenticity of tanzanite. With these precautions in mind, you can enjoy.
