What To Know
- To perform a hardness test, gently scratch the surface of the sapphire with a pointed object, such as a needle or a piece of glass.
- A gemologist can use a refractometer to measure the refractive index of a sapphire, helping to identify genuine stones.
- A gemologist can use a fluorescence lamp to observe the reaction of a sapphire to ultraviolet light, providing valuable information for identification.
Sapphires are precious gemstones renowned for their captivating blue hue and exceptional durability. However, with the prevalence of simulants and synthetic stones, it’s crucial to know how to test sapphire to ensure authenticity. This comprehensive guide will provide you with various methods to accurately identify genuine sapphires, empowering you to make informed purchases and appreciate the beauty of these magnificent gems.
Visual Inspection: The Initial Assessment
1. Color and Clarity:
- Genuine sapphires typically exhibit a rich, saturated blue color.
- Natural sapphires often have inclusions, tiny imperfections that add character to the stone.
- Synthetic sapphires may appear too perfect, lacking the natural inclusions found in genuine stones.
2. Luster and Brilliance:
- Sapphires possess a vitreous luster, characterized by a glassy, reflective surface.
- Genuine sapphires exhibit a lively brilliance, sparkling with inner fire.
- Synthetic sapphires may lack the brilliance and luster of natural stones.
3. Shape and Cut:
- Sapphires are typically cut into various shapes, including oval, round, and pear.
- The cut of the sapphire can affect its overall appearance and value.
- Be wary of sapphires with unusual or poorly executed cuts, as they may indicate synthetic or treated stones.
Physical Properties: Delving Deeper
1. Hardness Test:
- Sapphires rank 9 on the Mohs scale of hardness, making them highly resistant to scratching.
- To perform a hardness test, gently scratch the surface of the sapphire with a pointed object, such as a needle or a piece of glass.
- Genuine sapphires will not scratch easily, while softer materials may leave marks.
2. Specific Gravity Test:
- Sapphires have a specific gravity of approximately 3.95 to 4.10.
- To conduct a specific gravity test, weigh the sapphire in air and then weigh it submerged in water.
- Calculate the specific gravity by dividing the weight in air by the weight in water.
- Genuine sapphires will have a specific gravity within the expected range.
3. Refractive Index Test:
- The refractive index of a gemstone is a measure of how much light bends when passing through it.
- Sapphires have a refractive index of approximately 1.76 to 1.78.
- A gemologist can use a refractometer to measure the refractive index of a sapphire, helping to identify genuine stones.
Advanced Testing Methods: Ensuring Authenticity
1. Fluorescence Test:
- Some sapphires exhibit fluorescence, emitting a visible glow when exposed to ultraviolet light.
- The color of the fluorescence can vary depending on the type and origin of the sapphire.
- A gemologist can use a fluorescence lamp to observe the reaction of a sapphire to ultraviolet light, providing valuable information for identification.
2. Spectroscopic Analysis:
- Spectroscopic analysis involves examining the absorption and emission spectra of a sapphire.
- Different types of sapphires exhibit unique spectral patterns, allowing gemologists to identify the stone’s origin and authenticity.
- Spectroscopic analysis is a highly specialized technique typically performed in gemological laboratories.
3. Microscopic Examination:
- Microscopic examination involves using a microscope to study the internal structure of a sapphire.
- Gemologists can identify characteristic features, such as growth patterns and inclusions, that help distinguish genuine sapphires from simulants and synthetic stones.
- Microscopic examination requires specialized equipment and expertise, making it a common practice in gemological laboratories.
Final Note: Ensuring Confidence in Your Sapphire Purchase
By following the methods outlined in this comprehensive guide, you can confidently test sapphire and ascertain its authenticity. Whether you’re a seasoned gemstone enthusiast or a novice looking to make an informed purchase, these techniques empower you to identify genuine sapphires and appreciate their exceptional beauty. Remember, seeking the expertise of a qualified gemologist is always advisable for high-value sapphires or when in doubt about a stone’s authenticity.
FAQ: Addressing Common Questions About Sapphire Testing
1. Can I test sapphire at home?
While some basic tests, such as the visual inspection and hardness test, can be performed at home, it’s generally recommended to seek the assistance of a qualified gemologist for more advanced testing methods.
2. How much does it cost to test sapphire?
The cost of sapphire testing varies depending on the methods used and the gemological laboratory performing the tests. Basic tests may be offered at a lower cost, while advanced techniques, such as spectroscopic analysis, may incur higher fees.
3. Where can I find a qualified gemologist to test sapphire?
You can find qualified gemologists at gemological laboratories, jewelry stores, and gemstone appraisal services. It’s important to choose a reputable and experienced gemologist to ensure accurate and reliable results.
