Custom Wedding Rings with Natural Alexandrites

April 19th, 2014 by James L. Sweaney, CGA, FGA. GG
Alex ring 3:4

Custom Natural Alexandrite & Diamond Wedding Ring

Our client Laura has a passion for gems and fine jewelry, especially for natural Alexandrite. Her dream was to have custom wedding rings set with natural Alexandrites and Diamond. She found us thru the Mardon Blog and lives in the northern part of our state, so we’ve worked with her via email. We’ve made two custom rings for her recently, one of Diamond only, one set with Alexandrite and Diamond.

She’s been very pleased with our work so she asked us to make her new wedding set. She had a custom wedding band with small Diamonds and Alexandrites and an engagement ring with a one carat Diamond. She asked that we use as many of her gems as possible and add a pair of larger Alexandrites. She sent us this sketch as the basic look she wanted.

Alex sketches

Laura’s Sketch

Using her budget for the project as the parameters, we began by searching our network of gem traders for just the right stones and found these three matched pairs of natural Alexandrites.

Color Change_edited-2

Alexandrite Color Change

Besides images showing the color changes of the Alexandrites, we sent pics showing how they related to her one carat Diamond.

Alex & diam 2 pr

Alexandrites with Center Diamond


Since she wanted the new stones to be as large as possible, we focused on the two larger pairs. Although pair #2 were larger in diameter and more sparkly, #3 had more intense color, stronger color change and was a better match for her smaller Alexandrites so the choice was fairly obvious. Like everything in life, success is all about the choices we make– you can see from the finished piece that the Alexandrites match quite well.

The design process was rather involved. Laura sent us lots of pictures of leafy rings and several sketches. The problem with her sketches was that they weren’t to scale so they wouldn’t work with her stones. Also, she had more than enough gems to work with– the challenge was to fit them into her concept of leaves and vines. We sent a simple sketch done to scale to show the true proportion and relationships of her gem stones.

sketch of stone group

Sketch to Scale

Once we had her decision on which stones to use, we could start the CAD design. Here’s the first iteration– we grouped the Alexandrites together to emphasize their color. Because it would be a large ring, we suggested doing a single ring rather than a set.

Proof 1

Design Proof 1

She liked the basic look but wanted the color to be distributed throughout the ring, so we created this concept.

Proof 2

Design Proof 2

She decided that the engagement ring should be two tone. After considering the combination of rose and white, she chose yellow and white gold. She also realized she truly wanted a wedding band to match. After a number of tweaks and adjustments, we finalized this design.

Alex ring cad

Final Design Proof

To finish the rings, the prototype models were produced on our 3d printer, then cast with a traditional centrifical casting machine. That was the easy part. The two tone construction complicated our jewelers’s task– each yellow gold leaf had to be soldered individually to the white gold base–Tricky! He had to build support inside the delicate structure of the ring in order to be able to set the stones– he used the ancient method of melted shellac to form the support.

Making this custom wedding set was certainly a challenging task, but as you can see, the effort was worth it. The most important thing is that Laura loves her new wedding set. You can read her testimonial on our website.

Alex set

Finished Engagement Ring & Wedding Band

In making custom jewelry, the process can take many turns and twists. For this set, we had a total of 8 proofs before arriving at the final design. Although we at Mardon have been creating custom jewelry for over 40 years, we still learn as we go. The new technologies of digital imagery and computer aided design (CAD ) allow communication of ideas very effectively, while CNC machining and 3D printing have greatly improved production of the prototype. Combining these with the traditional hand craft methods of goldsmithing allows us to create superior pieces, yet the human element is still the key. Our Mardon team of creative experts stands ready to look and listen to your ideas to create the jewel of your dreams.




Antique Yogo Sapphire Pin

March 8th, 2014 by James L. Sweaney, CGA, FGA. GG
Yogo Pin w-pin

Antique Yogo Sapphire & Diamond Pin

A client inherited this gorgeous antique Yogo Sapphire pin and asked us to appraise it.

Sapphires were known to occur in several areas of western Montana as early as 1865. For the most part, these deposits produced only moderately good sapphires. The discovery of sapphires in Yogo Creek was different. In 1895, famed gemologist G.F. Kunz, working for Tiffany’s of New York, labeled them “the finest precious gemstones ever found in the United States”.

The Yogo stones are prized for their good clarity and wonderful natural color, often called “cornflower blue”.  Unlike the other Montana sapphires, the Yogo gems require no heat treatment whatsoever.

This fabricated pin features a carefully matched and graduated suite of gem quality Yogo sapphires estimated to weigh a total of ~ 3.5 cts. The style tells us it was made right around the turn of the century– to me, the delicacy of the design suggests the Edwardian style.

Yogo brooch back, w-pin

Yogo pin reverse shows removable pin and folding pendant loop

The pin was made specifically as a multi-purpose piece. The pin stem and catch both unscrew and the setting at the top of the circle has a fold up loop that can accommodate a fine chain. At one time, something dangled below the bow– you can see the little hook — but that is lost to the mists of time!

We’re members of the American Gem Society, antique jewelry buyers, restorers and appraisers, gemologists specializing in fine gemstones of all types and custom jewelry designers. Yes, we do it all, and we do it well. Stop by the shop and we’ll show you some of our unique jewelry. Open Tues. – Sat. 10 am to 5:30 pm.

Piece of Eight Silver Coin– Now That’s an Antique!

February 27th, 2014 by James L. Sweaney, CGA, FGA. GG
Atocha cross

Spanish Cross of Leon side, 8 reale silver coin


We were thrilled to acquire this pendant featuring an authentic Piece of Eight silver coin from the most valuable sunken treasure ever found.

In 1985, after 16 years of searching, famed (and persistent) treasure hunter Mel Fisher discovered the mother lode of all treasures off the Florida Keys. Valued at over 500 million dollars, the Atocha treasure contained tons of silver coins and bars along with gold objects, jewelry and gems.

On September 5,1622, heavily laden and bound for Spain from Havana with 28 other ships, the galleon Nuestra Señora de Atocha was driven on to a reef in the Florida straits by a hurricane. The immense treasure, which took over two months to load and record, was supposed to pay the debts of King Philip IV. As a result of this loss, Spain gradually withdrew from the Caribbean, leaving it to French and British influence. In a sense, the American Revolution, the Louisiana Purchase, the Lewis and Clark Expedition, and countless historical events in the Americas were directly linked to the wreck of the Atocha.

The peso de ocho, also known as the Spanish dollar, enjoyed world wide acceptance from 1497 onward. In fact, it was the coin on which the original United States dollar was based and remained legal tender in the US until the coinage act of 1857. Talk about historical significance!

These coins owe their odd shape to the method of manufacture. The Spaniards enslaved the indigenous people of the Americas to mine and mint these coins. After refining, the silver was cast into crude bars. The individual coins were cut from these bars, then clipped by the assayer to the proper weight. Once they were clipped, each side was struck with hammer and crude hand held dies.

Our attractive coin is mounted in a 14K gold frame and is suspended on a 20″ Byzantine style chain. The coin is from the Potosi Mint in Peru, dated circa 1618 – 1621– note the P mint mark on the Shield side. It’s almost 400 years since it was struck! Now that’s an antique!


Atocha shield

Spanish Shield with P mint mark

We have the original documentation and grading from Mel Fisher. It’s an 8 reale coin, grade 3. Our Potosi coin has the Cross of Leon on one side, showing the Lion of Leon and the Castle of Castile, while the reverse has the Hapsburg shield, the denomination, the mint mark and the assayer’s mark. 

You can still buy something very similar from Mel Fisher’s company for ~$2700. Ours, including the grand chain is $1250.

Our vintage and antique jewelry department is always brimming with surprises and delights. Stop by the shop Tuesday thru Saturday, 10 am to 5;30 pm to see this and other treasures.

Enameled Jewelry 101- A Historical Perspective

February 15th, 2014 by James L. Sweaney, CGA, FGA. GG

Chatelaine 1

We recently had the pleasure of examining this superb antique chatelaine. Centuries ago, the lady of the house wore the chatelaine, a strap or bag looped over a belt at the waist. Typically, the various tools necessary for her to deal with her daily tasks, items such as keys, scissors, watches, etc. were attached with chains. During the last half of the 18th century, the chatelaine became the in fashion among the aristocracy. This particular piece was obviously for the very wealthy– solid 18 karat gold beautifully decorated with rose cut diamonds, exquisite enameling and pearls. It was made circa 1780, just prior to the French Revolution by the watchmaker Robert Robin, a favorite of Marie Antoinette.

The chatelaine shows several enameling techniques. Enameling is an ancient decorative technique in which powdered glass is fused directly on to metal. We don’t know if Robin actually did the enameling on this piece– it’s likely that he had a specialist enamel his work.

The watch dial has an opaque white enamel base to which the delicate numbers, letters and decorations have been painted with an ultra fine powder of black enamel, then delicately fired.

Chatelaine Watch Front

Enameled watch dial with painted numerals

The back of the watch is a tour-de-force example of guilloche enamel, a variant of basse-taille enameling. Guilloche enameling is most famously seen on many of the magnificent Faberge eggs made for the Czar of Russia. The surface of the gold was engraved with a precise pattern by a special geometric lathe known as a rose engine. The pattern creates a truly dazzling effect beneath the vivid cobalt blue transparent enamel.

Chatelaine Watch back 1

Guilloche enameled back

The center is a dramatic whorl of rose cut diamonds set in silver– the jewelers of the time didn’t yet work with platinum or white gold. The diamond setting was attached via rivets thru special openings in the enamel. The pearls surrounding the enamel were natural Oriental pearls, most likely from the Persian Gulf or the Indian Ocean, set into the gold after the last firing and finishing of the enamel.

Around the edge, we see exquisite bright golden leaves within the enamel. The enamelist made these from hi karat gold foils. As seen by the uniformity of the decorations, he probably used a tiny die and hub like a cookie-cutter to cut the delicate foil. The foils were carefully applied to the enamel surface with special adhesive that would dissipate during the firing process, then covered with subsequent layers of enamel. The enamel was applied in many thin layers, firing the gold disc almost to melting over and over again. A piece like this could easily have a dozen firings.

Foil detail

Gold foil decoration

The chains of the chatelaine feature several different enameled components. This painted enamel panel shows a classic scene. The enamelist used ultra fine opaque enamel powders, ground almost to dust and carefully sieved, then applied like paints. The fineness of the enamel means the firing process is extra critical.

Chatelaine panel

Painted enamel, guilloche and foil

Chatelaine Detail 3

Reverse with guilloche, foil, and painted leaves

Chatelaine Detail 4

Painted enamel with gold deco


Jewelry enameling is not a lost art. Today’s artisans have the know-how but don’t often have the patronage to invest the hours required to make pieces like this. In subsequent posts, we’ll discuss the basics of enameling in more detail, show other techniques, and show more examples of period and modern enamels. Stop by Mardon to see enameled jewelry par excellence!



Antique Jewelry Shows Fine Craftsmanship

February 8th, 2014 by James L. Sweaney, CGA, FGA. GG
Edwardian Necklace

I-23222 Antique Platinum Necklace

This exquisite necklace from the Edwardian period, circa 1900-1915, exhibits the fine craftsmanship we associate with antique jewelry. The piece was made by fabricating and forming raw metals into the parts of the jewel. The main body and dangles began as thin sheets of platinum. The chain and bezels were made from hand-drawn wires and tubing. Many steps and hours of effort were required to bring forth this dazzling work. This magnificent example of antique jewelry really deserves a close look!

Jewelers of the period were fine artists capable of precise life size drawings. This beautiful design has elements of the Art Nouveau style with flowing whiplash lines and floral elements, yet the effect is more formal and refined than Nouveau. An actual size drawing was done on paper, then transferred to the platinum sheet.

Using a classic technique known as piercing, the jeweler drilled small holes at the openings in the design, then carefully removed excess metal with a fine jeweler’s saw. Even the delicate crescent shapes flowing from the flowers were pierced– a less exacting method used in this period was to make the crescents from fine wires which were then soldered into the openings

He constructed the three drop shapes from sheet and the round bezels from platinum tubes formed through a draw plate. The chain was assembled from tiny rings, soldered together one at a time. The five small bezels around the largest diamond were soldered into place.

Next, the jeweler shaped the piece using the chasing and repousse method. The work was placed on a surface of pitch that is firm but slightly yielding then worked with steel tools and a chasing hammer to push and “chase” the metal into the desired shape. The purpose was to add slight doming and subtle dimensions so the piece would be more dynamic.

After piercing and shaping, the diamonds were set into the main portion of the work with the bead and bright cut method. A hole smaller than the diameter of the diamond was drilled through the platinum and a seat was cut to fit the bottom of each diamond. The actual setting is accomplished by small curls carved directly from the platinum which shaped into beads on the edges of the diamonds with a beading tool. Excess metal is carved away from the stones to create a reflective “picture frame” effect and to leave free standing beads

Before the actual setting, excess metal was also trimmed under each seat by a technique known as azuring. The purpose of azuring is twofold– it allows the backs of the diamond to be cleaned easily and makes the piece lighter in weight. Azuring requires great skill and is time consuming, so it’s only seen on the finest pieces. The rest of the diamonds were set into the bezels and drops.


After setting, the jeweler applied a decoration called milgraining along the edges and around the settings. Tiny beads are created by rolling a special knurled wheel along the edges of the design. During setting and milgraining, the work was supported on a shellac stick or on the same pitch used for the repousse.


The sawn surfaces of the openings in the design were painstakingly finished with a technique known as trumming.  Strings or strips of cloth coated with polishing compounds were threaded into each opening and the piece would be moved back and forth along the taut strings until the surface was smooth and polished. Trumming a piece like this takes hours.

A rim of platinum known as the underbezel was fitted and soldered around the outer edge of the piece.The drops, bezels and chain were completed and attached. After the final polish and inspection, voila– a complete work of art!

You can see how much time, patience and skill went into creating this piece. Even the smallest detail was important. As a jeweler, I was surprised and delighted by the elegance and simplicity of the safety clasp at the back of the chain– just three rings of platinum and a strip assembled into an effective fail-safe clasp.

Safety clasp

These jewelry making techniques and methods have been developed over centuries and are timeless, passed on from jeweler to jeweler. This exuberant brooch from the 50′s was made in much the same way, fabricated from sheet and wire, diamonds bead set and azured. Notice how the backs of both pieces are as beautifully finished as the front.

50's Brooch details

I-23052  50′s brooch in 18K white gold

Stop by the shop to see these antique and vintage jewels– we’ll be happy to discuss the methods used and explain the technology of the time. And remember, we’re always interested in buying antique and vintage pieces– we’ ll soon find a new home where they’ll be loved and cherished.






Vintage Valentine’s Day Jewels

January 22nd, 2014 by James L. Sweaney, CGA, FGA. GG
I-23147 Elephant Pin

I-23147 18K gold, French enamel, diamonds and Burma rubies

Just in time for Valentine’s day, Friday, February 14– fabulous new goodies we recently acquired from a large collection of fine jewelry! If you are looking for something really special for that special someone, this group of vintage jewels may offer the perfect choice– we’ll highlight just a few items from over one hundred new pieces.

The estate contained many sophisticated pieces of 18K gold from France, especially whimsical animals, leopards and tigers (after Cartier), enameled ladybug earrings, turtles, frogs and other little critters. Our favorite is the utterly charming 18K white gold elephant brooch shown above, enameled and pave set with diamonds and vivid pinkish Burma rubies. Great for the political gal in this election year!

2Hearts Ring

I-23199 18K gold, Two Heart Beating as One, 2.5 cts tw

I call this dramatic 18K gold ring “Two Hearts Beating As One” because the two heart shaped diamonds reflect light from each other.

 TourmPearl brac

I-23169 18K pink Tourmaline & Pearls

This 18K gold pink tourmaline and pearl bracelet is elegant yet modern and stylish enough for everyday wear.

I-23150Tourm Earrings

I-23150 18K green & pink Tourmalines, 1.25 ct diam.

This striking pair of clip earrings from France features carved green tourmalines and faceted vivid pink tourmalines, highlighted with diamonds.

I-23197 Sapp brac

I-23197 18K 17.5 cts fancy natural color sapphires

One of the most unusual items is this 18K white gold bracelet set with over 17 carats of fancy sapphires- the beautifully matched pastel colors are natural color gems, no heat treatment, just as they come from nature.  And it has a matching pendant!


Mauboussin “Lady M”, 18K, Tiger’s Eye, 1.8 cts diam

If you love high end designer jewelry, this elegant “Lady M” bracelet watch from the famous French jeweler Mauboussin features a tiger’s eye dial accented with ultra high quality diamonds. While the original retail for the watch was a bit north of $30,000, our price is definitely “Take Me Home”

Last summer, we helped the heirs of this estate value the collection and then were privileged to buy when the time came. We offer superior professionally prepared appraisals for estates, and of course, are always interested in purchasing fine estate jewelry. Keep us in mind when you really need an honest and knowledgeable valuation for what you have.





Estate Jewelry- What’s Old is New

December 1st, 2013 by James L. Sweaney, CGA, FGA. GG
Art Deco pend


This spectacular pendant from the early 20th century highlights a parade of items new to our estate department. At 2 1/2 inches long, it’s just killer.  We haven’t quite decided just when it was made. The overall look is Art Deco, but the delicacy of the fabricated design suggests perhaps the Edwardian period. Regardless of its age, this grand 18K white gold dazzler is impressive and sure to catch the eye.

Edwardian bar pin


Our expert jewelers restored this lovely Edwardian pin. Hand made of platinum, it features a nice quality Old European center diamond accented with bright single cut diamonds and beautiful hand engraving. Sophisticated and elegant, the brooch will make a great statement for the professional woman. Former Secretary of State Madeline Albright famously wore pins and brooches to suit the diplomatic tasks of her day.



A striking example of the Art Deco style , our 18K white gold ring is set with bright Old Euro diamonds contrasted with calibre cut synthetic blue sapphires. Curiously, fine jewelry pieces from this period were usually set with synthetic sapphires rather than natural stones.

Cartier Solitaire




These classic platinum solitaires are from two of the most famous jewelry houses in the world, Cartier and Tiffany. Both carry ideal cut stones of very high quality. The Tiffany diamond even has the Tiffany logo laser etched on a star facet!

Both are perfect for the bride who wants a ring from a famous designer and the groom who doesn’t want to pay the designer price. The original sales receipt from Cartier for the brilliant 1.04 carat VVS2 G set in platinum showed the price paid at over $18,000 US. It is being offered for just $9450!

Jadeite&diamond earrings


These gorgeous well matched jadeite cabochons are suspended on earrings of yellow gold. The rows of beautifully articulated diamonds swing gently. The intense apple green color and soft texture of the jades is subtle yet striking.




For anyone who loves a big diamond and a great bargain (and who doesn’t), this light yellow round brilliant set in a contemporary halo setting of white gold is sure to please– Less than $6000 for a full 2 carat stone set in the white gold mounting studded with 1/2 ct of diamonds!

The really interesting thing about estate jewelry is the constant variety we see and the history these pieces represent. As active buyers of vintage jewelry, we’re constantly challenged to know what we’re buying as well as what is a fair price to the seller as well as to the ultimate consumer. If you are looking for a quality vintage item or have jewelry to sell, stop by our shop– we love to show and tell.





Natural Alexandrite Jewelry Sparkles Plenty

November 16th, 2013 by James L. Sweaney, CGA, FGA. GG


We just acquired these beautiful natural Alexandrite jewels from ABC Gems, our supplier who specializes in fine natural Alexandrites. For starters, the delicate pendant above features a round Alexandrite of excellent color change and clarity set in 18K white gold accented with diamonds.

Alexandrite was originally discovered in the Ural Mountains of Russia. A controversial story claims the gem was discovered on the 16th birthday of future Tsar Alexander II and so was named in his honor.  Like most myths, the grain of truth is that the stone was indeed named after Alexander, but it’s discovery was almost certainly earlier than the birthday.

Natural Alexandrite is one of the most rare of all the classic gems. A chrome bearing variety of the mineral chrysoberyl, Alexandrite has the unique property of true color change. In incandescent light, the original material from Russia appeared slightly purplish red, in daylight showing a soft grass green, so it was described as “ruby by night, emerald by day.” Today, the gem is primarily mined in Brazil, Sri Lanka, India, and Madagascar. The best stones usually come from Brazil, showing a strong color change from blue-green to reddish purple.

Alexandrites are graded first for the degree and quality of the color change, then for clarity and cut. Size is very significant in valuing this gem– stones over 1 carat are quite rare and can be very expensive in fine qualities.

Alexandrite is a very hard gem with a high refractive index, so it takes a fine polish and can be very sparkly. The hardness (8.5 on the Moh’s scale) means it is very durable and wearable, especially for rings like this stylish band.



Alexandrite is the birthstone for those lucky to be born in June. This sweet suite of matching pieces with leaf motif is perfect for anyone seeking an unusual and beautiful gem that is sure to spark conversation. Now showing at Mardon- we’ll be open 7 days a week during the month of December, so be sure to stop by and be dazzled!

Alex Leaf Set

I-22925, I-22926, I-22927

Imitation Gemstones– Buyer Beware

November 9th, 2013 by James L. Sweaney, CGA, FGA. GG

Three LookALikes

A client brought these three stones to our shop looking to sell them. She had purchased the stones while traveling and was under the impression the two 30 ct. greenish blue ones were aquamarines and the peachy pink stone was morganite.

At Mardon, as gemologists, we always buy gems very carefully and only when we know exactly what we are buying. The first things I noticed– that the greenish blue color was not quite right for aquamarine and the peachy pink was unusual for morganite– told me to proceed carefully.  A preliminary observation with my trusty gemological microscope indicated the “aquas” were not aqua and the “morganite” was not morganite.

Read the rest of this entry »

Secret Decoder Wedding Ring- In Rose and White Gold!

October 30th, 2013 by James L. Sweaney, CGA, FGA. GG


Dcodr groom side _edited-1

We just completed the most unusual wedding ring we’ve ever done- a Secret Decoder Ring, crafted of 14K white and rose gold and set with diamonds. Greg, one of Jenny’s best friends and an avid entertainment industry buff, had taken his fiancé Rebecca to a performance of “The Thrilling Adventure Hour”.  Greg and Rebecca had such a great time, the idea for an unique wedding ring came naturally from this plastic souvenir of the show. Read the rest of this entry »

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