Sapphire – Septembers Birthstone Part 2

/ / Gem Hunter Blog
This is a gorgeous 1.97ct, oval, blue sapphire from Sri Lanka

How To Evaluate Clarity In A Blue Sapphire

Part 2

(Judging Clarity For Non-Scientific People)


Hi, and welcome to this simple guide, on how to understand blue sapphire. Buying sapphires, especially blue sapphires, can be quite tricky. In my previous blog I discussed the basics of looking at color in blue sapphire. In this discussion I will emphasize on how to identify some of the clarity characteristics that determine value and desirability in blue sapphires. My goal is to equip you with some of the skills that you will need. In order to be successful in selling though, you will need to understand the basics, and then be able to convert your knowledge into benefits for your clients. In other words you will have to take what you learn today and be able to weave it into the fabric of your story  as you romance the stone. Learn to tell the story of sapphire as I have,  and above all have fun.

One of the most fascinating and rewarding aspects of gemology is the study of inclusions. These tiny bits of entrapped mineral, or structural irregularities reveal amazing clues about each gems personal history, of how it was formed and where it was born. Often regarded as flaws, which detract from a stone’s value, they are actually valuable clues that help unravel the secrets of a gem’s past. Inclusions often remind me of tiny galaxies and solar systems, trapped inside each gem, rich with minerals and mystery. Not only do inclusions speak to us of the place of formation, but they also serve as hallmarks of the extremely rare, processes which gave rise to each one. Flaws? No way. Without inclusions, how would we ever be able to distinguish these rare works of nature from, the cheap and mundane materials that are easily created in a lab.

 


Blue Sapphire – Clarity

Clarity grading for colored stones is actually quite different from the system used for diamond grading. First of all with colored gems all grading is done without magnification. That means that a grader is looking at the gem with the unaided eye. The gem is held in the tweezers, under a bright light source and judged based on the five criteria below.

GIA Has Developed A Five Tier Clarity Grading System

        • Eye Clean – This means that a trained grader, who is carefully looking at the gem cannot see any inclusions with their eyes.
        • Slightly Included – This means that a trained grader can barely see small inclusions, with the unaided eye.
        • Moderately Included – Inclusions are quite easy to see and at this point they are beginning to diminish the sparkle of the gem.
        • Heavily Included – This means that inclusions are very visible and possibly to the point that the strength of the stone may be compromised.
        • Severely Included – I call this material, (fish tank quality), for the fact that in my opinion, the gem is so filled with inclusions that it is best used at decorative fish tank rock.

        When you judge clarity, you are looking several clarity characteristics such as:

        Internal Crystals – Finger Prints – Cracks – Silkiness

        • Internal Crystals –  This is just like it sounds. In the crystalizing process other mineral crystals are sometimes trapped in the sapphire. Look at the images below and use your imagination in describing the rich internal beauty. Each gem truly displays a swirling galaxy of rare and stunningly beautiful minerals.

        • Finger Prints – These interesting inclusions often take on the appearance of a fingerprint, thus their name. Actually they are the remnants of cracks in the material that was partially healed or filled with molten sapphire, during the cooling process.

        • Cracks and Fractures –   These are just like they sound. They can either be stress fractures that travel through all or part of the gem, they can even be small and feather like or they can appear to look like a halo as in a stress fracture surrounding a crystal.

        • Silk – This is the haziness or a foggy appearance that will light up the interior of a gem, when you illuminate it from the side. Actually silk is generally the presence of fine rutile crystals, (titanium dioxide) which is actually one of the blue coloring agents in sapphire. The image on the right actually shows silk along with a very interesting zircon crystal carefully hiding inside this fascinating blue sapphire.


      • The key to looking at the clarity of  as sapphire,  is to illuminate it with a small flash light, from the side. This way any silkiness, any  cracks, needles or internal crystals will light up. Please remember though, that these fascinating characteristics are not necessarily undesirable, in fact, inclusions are the gems own fingerprint of origin and signature of authenticity.
      • You will also want to turn the gem over and look at it from the back side against a white background. In this way you will be able to see any color banding that might present Also, please remember, that sometimes interesting color banding in sapphire can actually increase the desirability and value of the gem.

    I hope this simple guide was helpful. As always feel free to reach out to us any time. Happy gem hunting and I hope to see you soon.