Blue sapphires are one of the most stunning gemstones in the world. Known for their deep blue color and elegance, they are a popular choice for engagement rings and other fine jewelry. But how can you tell if your blue sapphire is pure? Understanding the quality and purity of a sapphire is crucial before making a purchase or determining its value.
In this guide, we will explore various methods and factors to help you assess the purity of your blue sapphire. From examining its color and clarity to using scientific tools, this comprehensive guide will help you learn how to evaluate the gemstone’s authenticity and purity.
What is a Pure Blue Sapphire?
Before we dive into how to tell if your blue sapphire is pure, let’s first define what a “pure” sapphire is. In the world of gemstones, purity refers to how free the stone is from impurities and inclusions.
A pure sapphire is one that has no internal flaws, foreign materials, or colorations that would affect its appearance. However, it is essential to note that most sapphires, even those of the highest quality, contain minor inclusions. Pure blue sapphires are rare and highly valued in the gem world.
The Role of Color in Sapphire Purity
One of the primary factors in determining the purity of a blue sapphire is its color. The most desirable sapphires are those with a rich, deep blue hue. However, the exact shade of blue can vary, and impurities can influence this color.
Factors Influencing Sapphire Color:
Hue: The base color of a sapphire can range from light blue to deep, vibrant blue. Pure sapphires typically have a medium to dark blue hue without any secondary colors like green or purple.
Tone: Tone refers to the lightness or darkness of the sapphire’s color. A pure blue sapphire will typically have a balanced tone that is neither too light nor too dark.
Saturation: Saturation describes the intensity of the blue color. The more saturated the color, the purer and more valuable the sapphire is considered.
If your sapphire has any hints of yellow, green, or purple, it may contain impurities, which can affect its overall purity.
How to Check for Inclusions
Inclusions are natural imperfections found inside gemstones. While most sapphires will have some inclusions, the purity of the gemstone is influenced by the type, size, and location of these inclusions.
To check for inclusions, use a magnifying glass or jeweler’s loupe.
Here’s how to do it:
Clean the Sapphire: First, clean the sapphire thoroughly to ensure there is no dirt or residue on the surface that could obstruct your view.
Use a Loupe: A jeweler’s loupe is a small, high-powered magnifying tool that allows you to examine the gemstone closely. Hold the sapphire under the light and carefully inspect the surface and interior for any visible inclusions.
Look for Natural Inclusions: Inclusions in sapphires can appear as small bubbles, cracks, or foreign materials trapped inside the gemstone. These are not necessarily a sign of impurity, but large or visible inclusions can reduce the sapphire’s purity and value.
The fewer inclusions a sapphire has, the purer it is considered. However, it’s essential to remember that inclusions are a natural part of sapphires, and even the highest-quality stones will have some minor ones.
Identifying Synthetic Sapphires
One common issue that people face when purchasing blue sapphires is the possibility of buying a synthetic or treated stone instead of a natural one. Synthetic sapphires are lab-created stones that mimic the appearance of natural sapphires but may not have the same purity or value.
Here’s how to distinguish a natural sapphire from a synthetic one:
Look for Bubbles or Gas Bubbles: Synthetic sapphires often have small gas bubbles trapped inside. These bubbles are not found in natural sapphires.
Check the Cutting Style: Synthetic sapphires are often cut with a more uniform style, while natural sapphires may have slight irregularities in their shape.
Check for Color Zoning: Synthetic sapphires may exhibit unnatural color zoning, where certain areas of the stone are darker or lighter than others.
If you’re uncertain whether your sapphire is natural or synthetic, it’s always best to have it evaluated by a professional gemologist who can accurately identify the stone’s authenticity.
How to Determine Sapphire Purity Using a Refractometer
A refractometer is a tool used by gemologists to measure the refractive index of gemstones. The refractive index is an important indicator of a sapphire’s purity, as it reflects how the gemstone bends light.
Refractive Index of Natural Sapphires: Natural sapphires typically have a refractive index between 1.76 and 1.77.
Refractive Index of Synthetic Sapphires: Synthetic sapphires may have slightly different refractive indices due to the materials used in their creation.
By measuring the refractive index of your sapphire with a refractometer, you can determine whether it falls within the natural range for sapphires.
Use of a Microscope to Examine Sapphire Purity
Another way to assess the purity of a blue sapphire is by using a microscope. A microscope allows you to inspect the gemstone in much more detail than with a loupe, providing a deeper look at any inclusions, fractures, or color inconsistencies.
When using a microscope to examine a blue sapphire, pay attention to the following:
Inclusions: As mentioned earlier, inclusions are common in sapphires, but large or obvious inclusions can affect the purity of the stone.
Surface Condition: Check for any cracks or scratches on the surface of the sapphire. These imperfections may affect the overall purity.
Growth Patterns: Natural sapphires often have visible growth patterns or inclusions that are characteristic of their formation process.
Using a microscope provides a more thorough examination and can help identify any subtle signs of impurity or artificial treatment.
The Importance of Certification
When purchasing a blue sapphire, especially one that you suspect might be a high-quality or rare specimen, it’s essential to look for certification from a reputable gemological institute. Certifications from organizations like the Gemological Institute of America (GIA) can provide valuable information about the purity, authenticity, and quality of your sapphire.
A certified sapphire will come with a grading report that details its color, clarity, cut, and carat weight, as well as information about any treatments or enhancements the gemstone may have undergone.
Common Treatments That Affect Sapphire Purity
Many blue sapphires undergo treatments to enhance their color, clarity, and overall appearance. While these treatments are common in the gemstone industry, they can affect the purity of the stone.
Heat Treatment: This is one of the most common treatments used to improve the color and clarity of sapphires. Heat treatment can remove some inclusions and enhance the blue color, but it may also alter the stone’s natural purity.
Laser Drilling: This method is used to remove inclusions in sapphires. While it can improve the appearance of the stone, it may also affect its purity and value.
Filling with Lead Glass: Lead glass filling is used to fill cracks and inclusions in sapphires. While this treatment can improve the appearance of a sapphire, it compromises the stone’s purity and reduces its value.
When purchasing a sapphire, always ask the seller about any treatments the gemstone has undergone, as these can affect its purity.
Conclusion
Determining whether your blue sapphire is pure involves examining several factors, including its color, inclusions, and authenticity. By using tools like a jeweler’s loupe, microscope, and refractometer, you can gain a better understanding of your sapphire’s purity.
If you are unsure about your sapphire’s authenticity or purity, it’s always best to consult a certified gemologist who can provide an accurate assessment. Remember, a pure sapphire is a rare and valuable gem, but even sapphires with minor imperfections can still be beautiful and worth owning.
Related topic:
- Do Different Sapphire Colors Have Different Meanings?
- What Is the Princess Diana Ring Sapphire?
- What Is the Use of Yellow Sapphire Light Testing?
