Sapphires are one of the most coveted gemstones in the world. Known for their stunning beauty, they have been used in fine jewelry for centuries. But as with any precious gem, many synthetic versions are available, making it essential to distinguish between a real sapphire and a fake one. In this article, we’ll explore the key methods and techniques to determine whether a sapphire is real or not.
Introduction to Sapphires
Sapphires are a variety of corundum, a mineral composed mainly of aluminum oxide. While they are typically blue, sapphires come in a variety of colors, including pink, yellow, and green, depending on the trace elements present. Sapphires are highly durable, with a rating of 9 on the Mohs scale of hardness, making them ideal for daily wear in jewelry.
Due to their high value, many synthetic sapphires are produced to mimic the real thing. As a result, understanding how to identify a genuine sapphire can help ensure you’re not misled by fake alternatives.
Common Types of Sapphires
Before diving into identification techniques, it’s important to recognize the different types of sapphires on the market. The primary types include:
Natural Sapphires: These sapphires form naturally over thousands or even millions of years under extreme heat and pressure. Natural sapphires are typically more expensive and rarer than synthetic ones.
Synthetic Sapphires: These are created in a lab using heat and pressure to mimic the natural formation process. Though they have the same physical properties as natural sapphires, they are much cheaper.
Treated Sapphires: Some natural sapphires undergo treatments to enhance their color or clarity. Common treatments include heat treatment, which improves color, and lattice diffusion, which enhances clarity.
Now that we know the different types, let’s explore how to tell whether a sapphire is real.
Visual Inspection
1. Color and Clarity
The first step in identifying a real sapphire is to examine its color. Genuine sapphires have a vivid, rich hue. While they may have inclusions (small imperfections inside the gemstone), they should never appear too cloudy or transparent. A synthetic sapphire might display a more uniform color and fewer inclusions.
Sapphires with natural inclusions are known as “fingerprints” of the gemstone, and they add to the uniqueness of the stone. These inclusions are often microscopic and can be detected using a jeweler’s loupe or microscope.
2. Cut and Shape
Sapphires are typically cut into a variety of shapes, including round, oval, cushion, and emerald cuts. The cut should be symmetrical, with straight lines and well-defined edges. Synthetic sapphires may have cuts that are less precise or have visible imperfections.
3. Luster and Shine
Real sapphires have a brilliant, glass-like luster. This shine comes from the gemstone’s natural brilliance and the way light interacts with its surface. A fake sapphire might not have the same depth of shine, often appearing dull or flat.
4. Surface Scratches
One way to test if a sapphire is real is by checking for scratches. Sapphires are one of the hardest gemstones, scoring 9 on the Mohs scale. This means they should resist scratches from all other materials except diamonds. If the sapphire scratches easily, it may be a fake.
Magnification Test
Using a magnifying glass or jeweler’s loupe, examine the sapphire for any inclusions or other imperfections. As mentioned earlier, natural sapphires tend to have tiny imperfections that are unique to each stone. Synthetic sapphires, on the other hand, may lack these natural inclusions, or the inclusions may appear too perfect.
Look for any patterns within the inclusions. Synthetic sapphires often have more organized or repetitive inclusions, which can be spotted with magnification.
Heat and Pressure Tests
Sapphires are formed under high heat and pressure deep within the Earth’s crust. One simple way to identify a real sapphire is by performing a heat test. Place the sapphire under a heat source such as a flame for a few seconds. A real sapphire will not be affected by the heat and will remain cool to the touch. However, synthetic sapphires, especially those made from glass, can crack or melt under high heat.
It’s important to note that performing this test at home can be risky, so it’s always better to leave it to a professional jeweler.
Refractive Index Test
The refractive index (RI) of a sapphire refers to how light bends as it passes through the gemstone. Real sapphires have a high RI of around 1.76 to 1.77. To perform this test, a gemologist uses a refractometer, which measures how much light bends when it passes through the stone. Synthetic sapphires may have a slightly different RI due to differences in their chemical composition.
If you’re unable to access a refractometer, you can compare the sapphire to another gemstone of known RI to get a rough estimate.
Thermal Conductivity Test
Sapphires have high thermal conductivity, meaning they conduct heat quickly. One way to test this is by using a thermal conductivity probe. When the probe touches the sapphire, it will quickly become cool to the touch if it’s genuine. This test is quick and non-destructive, making it a reliable method for identifying real sapphires.
However, this test is best conducted by a professional jeweler to ensure accurate results.
UV Light Test
Another method to determine if a sapphire is real is by using ultraviolet (UV) light. Real sapphires often show a fluorescence under UV light, which can help distinguish them from synthetic stones. The fluorescence varies depending on the trace elements present in the sapphire. Natural sapphires tend to exhibit a bluish or violet fluorescence, while synthetic sapphires may show a weaker or different color.
However, this test should be done by an expert, as the fluorescence can also be influenced by heat treatments or other treatments used on the sapphire.
Professional Certification
For the most accurate and reliable identification of a sapphire, it’s always best to seek the assistance of a professional gemologist or jeweler. They can perform detailed tests using advanced equipment, such as a spectrometer or microscope, to examine the sapphire’s composition and authenticity.
Additionally, always look for sapphires that come with certification from reputable gemological laboratories, such as the Gemological Institute of America (GIA) or the American Gem Society (AGS). These certifications provide assurance of the sapphire’s authenticity and quality.
Conclusion
Sapphires are one of the most beautiful and enduring gemstones, but due to their popularity, it’s important to be cautious when purchasing them. By using the techniques discussed above, such as visual inspection, magnification, refractive index, and thermal conductivity tests, you can confidently determine if a sapphire is real or not. However, for the most accurate results, it’s always best to consult a professional.
Understanding how to identify a genuine sapphire will not only help you make more informed decisions when buying sapphire jewelry, but it will also ensure that you are investing in a high-quality and authentic gemstone.
Related topics:
- How to Choose the Best Yellow Sapphire for Your Jewelry?
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- How Old Are Natural Sapphires?
