Welcome to the Gilt Trips podcast. I'm your host, Kendra Lockhart. As a goldsmith and
gemologist, I'll be speaking 24 carat on all things jewelry, metals, and gems. Join
me plus a few friends to demystify both materials and designs as your private jeweler. Let's
tune in on these topics and get golden. The master, Gordon Ramsay, has said that a chef
is only as good as their knives. I say that line of thinking is much more truthful for
a gemologist and the equipment at hand. A gemologist is someone who has to have two
minds, one of a librarian and the other around forensics, because gemology is a branch of
mineralogy that trains and certifies us. We become people who identify and grade precious
gems and jewels. What tests and tools help identify jewels? Why does it matter to know
what category gems are in? We'll answer that in today's episode. Chapter timestamps are
in the show notes. I have two jobs currently. One is in an office where I have a mini lab
and one is offsite where I have a field kit. So I'm going to break it down into which can
be portable devices and which have to stay put in the office. The first is a loop, which
is a small, simple lens-based magnification device used to see details. Today's standard
is a 10 power loop, but I often use 45 power when I need to find inscribed serial numbers
on lab-grown diamonds. The former is required to view and assess a diamond's clarity so
that you can assign it a grade. That just needs a 10 power. Now I've got colleagues who have
treated themselves to a loop with a case and a handle made out of yellow gold and very
elaborately engraved. There's a romance to be jeweling the piece that you need to use
to look at expensive gems, but I'm also a bit of a minimalist and I like my equipment
straightforward, so to each their own. Next are the gauges. A leveraged gauge or a digital
gauge. They'll be used for precise measuring of either diamonds, for example, or a whole
piece, metal thicknesses. A leveraged gauge or the digital gauge are both hand-held tools
that make precise measurements of an object's length, width, depth, or thickness. They are
easy to use and read and can display measurements in both metric and imperial units. The leveraged
gauge has a manual dial with markers, kind of like a watch. The digital version computes
the number for you. Technology does make it easier and more user-friendly when you don't
have to be the human calculator if the device is going to do that work. In either case,
the dial is held in the palm of the hand and your thumb operates the slider so that you
can spring it open and insert the gem or ring or component you want to measure. The two
walls spring closed on your piece and the gauge will read the difference into a number
for you. Digital calipers are a lot like the gauges except the sliders integrated into
a ruler. I can get readings down to 1,000th of a millimeter. I can switch the display
into inches and even lock the calipers in place with a rotating knob. This helps me
with much larger items like measuring a watch case, where the gauges would get maxed out
since they're designed for smaller items. In my field kit, I also have tweezers and
grips. If the gem is loose, your fingers are going to be too clunky or big, especially
if the jewel is tiny. You will need your metal tweezers, which are held between the thumb
and fingers, to grab and manipulate the gem. I use tweezers mostly in combination with
my loop so that the item is steady and not getting all finger printed up. If it's a
larger stone, it also helps me hold and lock while handing to a client to view. This makes
combining with a loop, onsite, offsite, or in meeting very simple.
An alternative to tweezers is the gem grip. It's like a ballpoint pen, but when you push
the bottom, four retractable prongs come out and hold a gem from its table to cue it, or
vertically and not from either its length or width. Again, this comes in extremely useful
to capture a loose stone and be able to pass it from gemologist to client and then back
to us. And now, the elements in what my office has that constitute a mini lab. First is going
to be the microscope. This is a complex instrument that helps to uncover many traits of gems
and jewels that you will be determining. Words like dark field, bright field, and diffused
are going to refer to the type of lighting needed to find identifying inclusions, or
striay, or color zoning. You may hear refracted light, which will expose surface issues, pinpoint
lighting, and that can be achieved with opening the baffle and closing down the iris. Oblique
lighting will help you see horizontal pinpoint crystals, bubbles, or flux inclusions. If
it sounds like a heavy lifter of your equipment options, it's because it is.
The refractometer. One test to determine the gem's identity is to measure the refraction
of light with the gem. Essentially, when light passes from one substance to another, it bends.
Blue light bends more than red light. How much the light bends will vary depending on the
gem's mineral composition. Every material has a critical angle, meaning, at a certain
point, light is reflected back internally. This can be measured and thus used to determine
the gem's identity. Typically, that is found with the refractometer. I have a liquid that
I put between the light source lens and the facet of the gem before I look through a viewfinder.
The number I find correlates to refractive indexes. If I get a 1.76 to 1.77, I am working
with ruby or sapphire and not glass. A polariscope. This is a critical tool used to determine
how much light is bending through the gem. With a polarizing filter and a light source,
this device will help a gemologist determine if one ray of light is returning, called singly
refractive like a diamond, or if I am getting two rays exiting the material, making it doubly
refractive like moistenite. The polarizing filter works by blocking out the light except
in a single direction. A diacroscope is like a little tiny spyglass that works with the
doubly refractive material and lets the gemologist know if more than two colors will show. When
you look through a lens, it shows two side-by-side square windows in the view. The tool is made
up of internal prisms plus calcite, a material that also bends light. So, single ray, or
single refraction colors stay the same. Two ray, or double refraction, you will get two
different colors. But what do you do when there is more? That word is called pleochroic,
meaning multicolor, and material like tansonite has this trait. You will rotate on all the
axes, twirl 90 degrees, the colors will switch frames. This helps you determine the difference
between a tourmaline, which is diacroic, or shows two colors through this instrument,
and aylite, which is pleochroic, like tansonite. It also helps diagnose natural versus synthetic
ruby because the colors that come back to the eye are completely different. A spectroscope
uses a similar principle to how a prism works to separate white light into its component
colors. A gemological spectroscope is employed to analyze the selective absorption of light
in the gem material. Coloring agents show bands in the spectroscope and indicate which
element is responsible for the gem's color. This instrument is also like a tiny little
spyglass held up to the eye and directed towards a light source with the gem in front of its
end. You will see a visible spectrum, like a section of a rainbow, with absorption lines.
These dark lines correlate to the chemical makeup. It will form a pattern that will help
you match it up to known images of identified gems. I like to say it creates a quote unquote
barcode that we can look up in a book with images and find its match.
The Chelsea color filter is an important lens that allows me to identify certain green, red,
and blue stones. Mainly it assists us when we are detecting dyes in certain gems, like
dyed green and blue calcidine. Fluorescence is when a gem starts glowing under ultraviolet
lighting. Phosphorescence is when a gem stays glowing after removing its exposure to ultraviolet
lighting. The equipment for using UV can either come as a flashlight, which I can use in the
field, or a light box that we have at our office or mini labs. The most important use
of UV is diagnosing heat treatments on rubies and sapphires, or certain types of filler
and emeralds. And in the world of jewels, the big three, those gems, mean thousands
of dollars difference in natural versus enhanced colors, so this is critical equipment.
The GIA ID 100. What do we need when it comes time to discern earth diamonds from lab grown
diamonds? We need this tool. Using spectroscopic technology plus GIA's decades of diamond and
gemstone identification research, their machine can distinguish natural diamonds from laboratory
grown, which show their methods, whether they're high pressure, high or carbon vapor deposit,
and thus recognizing the diamond source material as well as certain simulants. The Duo Tester
is what I use most out of all of my equipment. If I need to get varieties and gem species,
this combines thermal conductivity and reflectivity indexes. A thermal current goes through a pen,
like a wand, and then shows up on a gauge. It can separate things like quartz material,
limoline, glass, spinel, ruby, sapphire, and diamond. The Gem Identification Manual. This
is the bible of gems, minerals, synthetics, composites, you name it. It rolls all the tests
that I've been outlining into how to confidently make the call. When you've done all your
paces on a gem, and some are diagnostic with certainty, and some are inconclusive, taking
all of your data and cracking open the book to cross check your results into, hey, this
gem can only be XYZ. It's pretty satisfying, and you know your puzzle is solved.
The biggest and best tool you use is none other than your mind, and that's going to
come with a great education. The curriculum that creates gemologists originated in 1929
by Robert Shipley, who would later establish both the Gemological Institute of America,
known as the GIA, as well as the American Gem Society, or abbreviated as AGS.
I'm personally very lucky that I went to the campus at a time the GIA was expanding into their
current Carlsbad headquarters. According to the Dean of Students, the GIA is a commitment
for the mission of consumer protection and providing information in their interests.
Why I went there is because of the three ways that the GIA is designed to serve the industry
and the public. One, it offers lab services to provide a third party evaluation between buyer
and seller. So we were already using those when I went into my Goldsmithing apprenticeship.
It's the lab report you would get on your diamond. It would be a treatment report that you would get
on colored stones. Two, it delivers an education that trains us to go into the lab or become an
ambassador of what happens with lab services out in our jobs around the world. And three,
the research. According to Kimberly Overland, the Dean of Students, quote, we have PhDs and
researchers on staff that are constantly looking at the industry, looking at stones, looking at
changes and new findings and treatments, unquote. And that gets shared in the media we subscribe to
and the symposiums we attend to stay on the razor's edge of priceless knowledge, developments,
and techniques to hold true to the integrity that gemology is.
Thank you for listening and learning with me. I would love you to share this project with people
finding rare beauty in today's world and throughout our times. Until the next episode, keep your own
story sparkling.