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Gemology school

Introduction

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Gems are a mystery until you can prove their identity. Once you know the identity, a ruby, a red spinel, or an almandite garnet then and only then can you appreciate it for its true qualities.

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At first glance, many gems look alike. Others have a unique appearance. In all cases, the possibility exists that the appearance of one gem may be duplicated by a man-made material or another natural gem material.

The correct identification of a gem is essential before any consideration can be given to quality and value. This process must be worked through carefully to avoid costly errors.

 

Getting organized before start examining gemstone

You can almost always learn something from a gem’s appearance before you go on to more advances gemological testing. An obvious characteristic speeds up the identification process because it lets you rule out those species and varieties the stone can’t possibly belong to. Knowing what a gem isn’t narrows your choices down to a more manageable number. Here are list of few elements that better get prepared before start examining stones.

A.)  The right lighting-You need good light to examine gems with a loupe, one bright enough to let you see what you need, but not so bright that you get too much glare.

Most types of interior lighting will work such as table or desk lights, as well as penlights and sunlight.

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Daylight sources:

  • fluorescent tubes marked “daylight equivalent”
  • the overhead fluorescent light on a gemological microscope

Incandescent sources:

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  • standard light bulbs
  • high-intensity lamps
  • small, battery-powered flashlights—penlights
  • the fiber-optic system

Use a neutral background. Avoid any background that shows color: Pure white is best, light gray is second best. There are many possible white and light gray backgrounds, including sorting pads and cloth-covered trays.

For consistent results with different gems, always use the same lighting and background. If that’s impossible, consider the ways different lighting and backgrounds affect a gemstone’s appearance—especially its color—and compensate for that effect. “Just remember never to look directly at a strong light source through your loupe.”

Holding the gem in the right position relative to the light source, your eye and the loupe is important, and easily learnt by trial and error. Sometimes you will want light to shine right through the stone, sometimes reflect off it so you can best see the surface.

B.)  Knowing how to use tweezers is essential when examining gems.

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  • To examine a stone face-up or pavilion up, hold it at the girdle —girdle-to-girdle.

Girdle-to-girdle pick up — turn the stone table down on a clean, flat surface. Align the tweezers with the stone’s girdle by resting them on the surface and squeeze the tips together around the stone.

To examine the gem from the side, hold it table to culet.

  • Table-to-culet pick up — place the stone table-down on a gem cloth, then slide one tip of the tweezers under the table and center the other on the culet. Don’t squeeze too hard—the culet is the most vulnerable part of the stone.

C.)  Cleaning up stones

  • Lay the gem cloth flat with the fuzzy surface up.
  • Fold it in half and in half again, with the second fold perpendicular to the first. The folds should leave your cloth divided in quarters with the fuzzy surface on the inside.
  • Turn one corner of the top layer back so a soft crease forms diagonally halfway across the layer.
  • Place the gem on the flat, exposed fuzzy surface.
  • Cover the stone by unfolding the layer you folded back.
  • Grasp the stone between your thumb and index finger through that layer.
  • Raise the stone slightly above the flat, lower layer, and rub it between your fingers with the cloth, using a brisk, scrubbing motion.
  • Turn the stone as you rub until you’re sure you’ve cleaned every surface.

D.) Examining the Gemstone by using Eye-Loupe

You can think of a gemologist as a gem detective, someone who uses their knowledge, their experience and their observations to identify an unknown gem. As a gem detective you need knowledge and experience, and also certain equipment. We might as well start with that old symbol of detection, the magnifying glass. The large lens that Sherlock Holmes brandished over clues is no use in gemology. You need higher magnification and the standard used by a gemologist is ten times what we call 10x lens or loupe.

Although, the 10X loupe is one of the most basic and essential tools that an industry professional can own. However, it is important to learn to correctly hold and use your loupe, something we’ll look at from below step by step instructions:

  1. Turn on the light source and position it at a convenient height for working—a little below eye level is fine. Make sure the shade keeps light from shining in your eyes. If possible, turn off other lights in your workspace.
  2. Clean the stone thoroughly with a gem cloth or, if it’s very dirty, use warm soapy water and a soft brush. Make sure the lens of the loupe is also clean: Use lens cleaner and lens tissue.
  3. Pick up the loupe. Insert your index finger into the metal cover and use it for a handle.
    - If you’re looking with your right eye, try holding the loupe with your right hand.
    - If you’re using your left eye, hold the loupe with your left hand.
    - “Crossover” style — right hand, left eye or left hand, right eye. Try both ways to see which is the most comfortable.
  4. Pick up the stone. (see next slide)
  5. Position the loupe and stone for examination.
    - Hold the 10X loupe close to your eye.
    - Hold the stone about an inch from the loupe.
    - To hold everything steady, rest the hand that’s holding the tweezers against your loupe hand, and your loupe hand against your cheek.
    - If you wear glasses, you can rest the loupe against them.
    - If you’re sitting at a desk, rest your elbows on it.
    - If you’re standing, or can’t rest your elbows, hold your arms to your sides.
  6. Examine the stone carefully and thoroughly, turning it so you can view it from every angle.

Explore our fantastic gemstone inventory here