Dazzling Gems to Delight You
By “Awake!” correspondent in Brazil
“CAN I help you, Madam? You would like to choose a gem? Of course. Is it to be an earring, a brooch, a bracelet, a necklace or a ring? What is your favorite color? Let me show you some gems. This is a difficult choice? I agree, they are all beautiful.
“The price? Well, diamonds are tiny in size but big in price. Quartzes are big and showy but smaller in price. How about this sparkling yellow citrine? Or this amethyst? Do you like its violet glow? Ah, the lustrous aquamarine?
“You wonder whether you could see how such a stone is cut? Of course. Let me show you to the workshop. But be prepared for a shock. Raw gemstones are nothing like their cut and highly polished counterparts.
Cutting and Polishing
“See? No brilliance here, just unsightly pieces of rock or dull crystal formations. Like this ‘worthless’ piece of rock crystal? But wait. The gem cutter holds it up against the light. Can you spot a hidden glimmer of light inside? What stone is it? Aquamarine. Indeed, what a difference from the polished gem you saw on the counter!
“The gem cutter insists on your witnessing a spectacular transformation. Watch his deft fingers. With quick and sure movements he saws the stone with a diamond saw. Then he shapes the outline on a carborundum wheel.
“What decides the final shape of the stone? Since the value is related to the weight or number of carats, he seeks to get the most out of the rough stone. The demonstration piece suggests an oval gem.
“See how the stone is impressed in sealing wax on the end of a pencil-shaped ‘dopping stick’? It is now ready for faceting. With the pencil tip leaning against an adjustable angle support, the gem cutter barely touches a revolving tin-alloy wheel with the stone. Very fine emery powder on the wheel grinds or cuts faces in the stone. Water is constantly sprayed on to avoid overheating, which would ruin the gem.
“First, he grinds the flat top. Next, he cuts a facet on one side, then on the exact opposite side, and so on. The geometric disposition of facets is to bring out the beauty of color and light in transparent gems. The top side done, a light polish around the girdle will prevent the stone from cracking.
“Now he softens the wax over a lamp, pries out the stone and turns it over. Once again, facets are cut, but two more than on the top, for more effective refraction of light.
“Yes, indeed, the lower part resembles the curved bottom of a boat. But where is all the luster, you wonder?
“This is the job of the polisher and his copper wheel. Watch. Skillfully he goes over each dull face at exactly the same angle. One facet after the other begins to light up. Really, the buffing brings out all the hidden ‘fire.’ Fascinating! From a dull piece of crystal emerges a dazzling gem in just about 40 minutes!
“Sure, you may pick it up. What an exquisite bluish-green sparkle, partly due to the facets! Faceting produces brilliancy by the reflection and refraction of light.
What Are Gemstones?
“How do we get gemstones, and what are they? Most gems are minerals produced by natural inorganic processes. Each mineral has its own atomic structure and chemical composition. Of the more than 1,600 mineral forms, only about 16 excel because of beauty, color, hardness, brilliance and rarity. Meeting these qualifications, they are called gems. The harder ones are rated as precious stones, and those below the number 8 on the hardness scale are considered semiprecious.
“You are right, knowledge of the crystalline structure is invaluable to the cutter. If a stone is not cut accordingly, it may crack or break.
“What makes color? Most gem minerals are colorless when pure. The diamond, for example, is more valuable colorless. However, what produces color in other gems is still not fully understood. Of course, it is true that chemical impurities may play a part. But, then, the same trace chemical may color one gem red and another green, as in the case of the ruby and the emerald.
“How the expert identifies a stone? He takes into account color, crystal form, weight, optical and other physical properties, also their chemical composition. Usually, the tests include one for hardness, specific gravity and refraction. These qualities vary from one kind of gem to another, but they remain the same for every kind.
“Hardness is based on Mohs’ scale of hardness. The harder a gem the more durable and valuable it is, as it can be given a higher polish. All the higher-grade minerals can scratch those of a lower grade when rubbed together. The highest number is 10, for the diamond, while the quartz family registers 7. In comparison, a steel knife rates 6.5, and the hardness of your fingernail is about 2.
Sparkling Brazilian Gemstones
“Why not return to the showroom now and continue your choice of gems? By the way, Brazil supplies about 90 percent of the world’s colored gemstones. In no other part of the world are they found in such spectacular variety and abundance.
“You still like that fine aquamarine, don’t you? Well, it is the most popular Brazilian gemstone and belongs to the beryl family, just like the emerald. I will show you the different hues. See? From bluish green to dark blue. Like the clear waters of the blue sea? Exactly, that is what aquamarine means.
“Let me tell you the story of one rich find. In 1955 a man was chopping down a tree with his machete when it missed and hit the ground, knocking on a rock. Surprised, he dug it out and at first thought it was a valueless piece of rock crystal. But how much more surprised he was when it turned out to be one of the most beautiful aquamarines ever found. It was cut into numerous individual stones, totaling 80,000 carats, at an estimated value of two million dollars [U.S.]!
“You like the citrine? Really, some call it quartz topaz, but beware of those who call it just ‘topaz,’ for it is not. Although a lovely stone, citrine belongs to the quartz family. Its warm golden shades endear it to millions. The yellow is probably caused by traces of iron in the crystal.
“The difference between citrine and precious or imperial topaz? Imperial topaz is not a quartz and is much harder, in fact, it is number 8. Therefore its brilliancy is far stronger. It is a very rare stone, especially in sizes above 10 carats. The blue, pink and light-green varieties are among the loveliest gems. Due to its rarity it is several times more expensive than citrine.
“You have heard of the ‘mineral of a thousand colors’? It is this one, the tourmaline. Examine these specimens. No two are the same. Its complex chemical composition includes various metals and substances. Even a single crystal is rarely uniform in color, but of contrasting tints—one of the wonders of the mineral kingdom.
“You always thought that tourmaline was only green? Indeed, the best known is green, but there are blue and red varieties too. Unlike aquamarine, the lighter shades of tourmaline are held in great esteem. The best green is that nearest the emerald shade. There are yellow, pink and white beryls. Garnets, opals, moonstones, chrysoprases and rose quartz are also abundant in Brazil. The green chrysoberyl is of extraordinary brilliance and is extreme in rarity.
“For diamonds, one looks nowadays to South Africa. But, before diamonds were discovered in Africa, Brazil once enjoyed a virtual monopoly. The 120-carat “Southern Star” is of Brazilian origin. No doubt, diamonds are the most widely known and the most prized precious stones. You would hardly believe that it is chemically pure carbon, the same as graphite. Naturally it is of a different crystal form.
“A well-cut diamond can produce all the colors of the rainbow. Brazilian diamonds are alluvial, that is, they are found only in the gravel along riverbeds.
How to Care for Your Gems
“With a little care, your gems will always delight you. But even a diamond, although proverbially being forever, can lose its brilliance because of dust particles on its surfaces.
“So, before washing your hands or applying cosmetics, be sure you are not wearing your gem. Soap, creams and talcum powder obscure its brilliance. Do not strike hard surfaces with your gems. Although diamond is the hardest known substance, yet it can be scratched by another diamond. To prevent this, wrap gems separately or keep them in separate jewel boxes.
“For its radiance to continue, a gem needs to be kept clean. This can be done by soaking it in a warm solution of two cups of water, a teaspoon of ammonia and a bit of soap powder or any good detergent, brushing it gently to remove dirt. Having done this, rinse in plain warm water, then dip in some alcohol to get rid of any soap that might still be left on it. Leave to dry in a soft absorbent handkerchief.
“You have now made up your mind, Madam? Yes, of course, the citrine and the aquamarine. Really, they are beautiful. Thank you. Always at your service with our dazzling gems to delight you!”