GIA iD100 Diamond Tester at Mardon Jewelers

March 3rd, 2018 by James L. Sweaney, CGA, FGA. GG

Mardon Jewelers just acquired the latest diamond testing device from the Gemological Institute of America, the GIA iD100. This desktop instrument uses spectroscopic technology to separate synthetic and imitation diamonds from natural diamonds. The GIA iD100 was developed to inform and protect both jewelers and consumers.

Because of recent technological advances, laboratory grown diamonds are now widely available in sizes suitable for jewelry. Synthetic diamonds aren’t easily identified by normal gemological testing. Most companies label their product with laser etching on the girdle, but unmarked stones are showing up in the market place, posing problems of disclosure.

For centuries, natural diamonds have been valued highly because they are beautiful, durable, and rare. Synthetic diamonds are now being mass produced, so they are not rare. Since synthetic diamonds usually sell for about one third the price of natural diamonds, it’s very important for jewelers to know what they are selling and for consumers to know what they are buying.

The GIA iD100 gives very straightforward results quickly and can used to show consumers whether a diamond is natural or synthetic. Over 98% of natural diamonds are type I while all synthetic diamonds are type II. The tester recognizes the luminescence of type I diamonds and gives them a “Pass”. Synthetic and imitation diamonds generate a “Refer” signal, meaning further study is needed to identify the stone. Type II natural diamonds also referred, but these are very rare. Gemologists usually identify type II natural diamonds by natural inclusions and other characteristics.

As part of our appraisal and buying services, Mardon is proud to offer the latest methods for evaluating jewelry and gems. Even though new technologies like the GIA iD100 are very expensive, we know these investments are worth it in the long run. By keeping up with these new developments, we’re able to offer the best merchandise and expert services available to our clientele.





8 Reasons For Custom Jewelry

January 26th, 2018 by James L. Sweaney, CGA, FGA. GG

People have many reasons for wanting custom jewelry.  Sometimes, they want something new and exciting, sometimes they need a problem fixed, sometimes it’s to replace or recreate a special piece. The artisans of Mardon solve all sorts of design requests and challenges– in addition to our in-house design services, we work with the best crafts people in the business for expert hand engraving, stone repair, and enameling.

Custom Hand Engraved Wedding Bands

Owning unique one-of-a-kind jewelry sets us apart. This couple wanted easy to wear wedding bands with a vintage style. Designer Jenny Sweaney created this original floral design reminiscent of the Art Deco style. The open work is perfect for hand engraving. These beautiful wedding bands will make this couple’s ceremony memorable and will draw admiration for their marriage in the years that follow.

Perfectly matched GIA graded Diamonds

This gentleman wanted a simple elegant ring with a matched pair of high quality diamonds to celebrate his 40th anniversary. We found the perfect diamonds and followed his suggestions for the design.

Old Mine Cut Diamond in a Modern Style

After many years of marriage, this lady wanted a new wedding ring. She  had a good idea what the design should be- We adapted her idea to her gems. Along the way, we recut her chipped Old Mine cut family diamond. We like the combination of an antique diamond with this modern look– it really works.

Men’s Lost Wedding Band Recreated in Platinum and Rose Gold

This man lost his unusual wedding band– we recreated it in platinum and rose gold with princess cut diamonds.

Sapphire and Diamond Ring, redesigned

This client kept losing sapphires from her ring. It was a design flaw that wasn’t repairable. We re-engineered the design with more secure settings for her stones while keeping a similar look. Now her new ring is problem free.

Gorgeous Natural Jadeite in 14K Gold

This lady received a wonderful natural Jadeite from friends on one of her many trips to China. Our custom setting shows off her gorgeous gemstone and suits her lifestyle to a T- She was ecstatic with the result!

Imperial Topaz and Baguette Tsavorites in Rose Gold

This shopper bought a fine Imperial Topaz in Brazil and wanted an unique setting. We matched it up with a perfect pair of rare Tsavorite baguettes. The step cutting, the colors of the gems and the rose gold work together in beautiful harmony.

Pallasite Peridot from the Stars!

This pair of custom earrings features gems that are literally out of this world! This couple waited for two years for a specialty lapidary firm to locate and cut this matching pair of Pallasite gems. Pallasite is an unique variety of peridot– the Pallasite crystals form within meteorites and fall from the heavens! CAD whiz Jenny Sweaney worked for several weeks developing the perfect design to show off these ultra rare gems and to express the couples’ feelings for each other.

Custom made jewelry is a Mardon specialty. It’s one of the special parts of our skill base that keeps us looking forward to our work each day.

Our state of the art CAD jewelry design software allows our clients to participate in the design process and to see precisely what their jewelry will look like before it’s made. We produce castable models with a 3-d printer, a computer controlled milling machine, as well as by hand carving. You can see from these examples how versatile custom jewelry can be.

If you have need for custom jewelry or just want to ask questions, stop by our shop anytime during business hours, Tuesday thru Saturday, 10 am to 5:30 pm. We’ll be happy to show you how it works. You can call 951 682-2325 or email



Art & Crafts Pin

November 21st, 2017 by James L. Sweaney, CGA, FGA. GG

We recently acquired this sweet little diamond and 18K gold pin from the late 19th century. It’s a perfect example of the ideas behind the Arts & Crafts movement– made by traditional fabrication methods using simple tools to create simple forms and styles of decoration.

The jeweler made the main stem of the piece by forging 18K gold wire into a tapered form. He used a jeweler’s hand saw to split the large end of the taper to form a Y to which he added a crescent wire of gold. He soldered the stem to the diamond setting which is composed of three concentric circles held in position by gold cross bars. Notice how he curled the ends of the Y into a simplc decorative element. A pin assembly was added to complete the metal work, then the diamond was set and the pin polished. We’ve left the patina of age on the pin.

The most interesting part of the pin is the innovative way the jeweler made the pin catch. It’s just a gold wire loop formed into an elegant S shape, soldered to the back of the main tapered wire. A gold wire attaches to and stabilizes the loop on one side, while the opposite side is left open for the pointy end of the pin stem to fit into. The wire is perfectly shaped to cover the sharp end of the stem.


The simplicity of this important part of the jewel is remarkable, especially when you compare it other pin catches of the period and after. Most have moving parts which have to be properly aligned in order to work properly. They can be tricky to operate and are easy to bend out of shape.

The ingenuity of this jeweler to create a perfectly functional catch with no moving parts using basic materials and hand tools is the essence of what the Arts & Crafts movement was all about. These ideas are still important today and are often expressed in the jewelry of the Modern Period. See Mardon Blog ,

At Mardon, we always adding new items to our estate department. Not only are these items beautiful, they often teach us about our history, not only of jewelry but also of our culture. We incorporate these lessons into many of the original and custom works we create right here in Rivcrside.

Stop by at our new location soon, at the Canyon Crest Towne Centre, next to the Rite Aid.  Starting Tuesday, November 28, we’ll be Open 7 Days A Week for your shopping convenience, Sunday thru Thursday, 10 – 5:30, Open Late, Friday & Saturday, 10 – 8 pm.

Gold Buckles

October 25th, 2017 by James L. Sweaney, CGA, FGA. GG

Our latest find in the Estate Department is this beautiful pair of gold shoe buckles. They are fabricated of 14K yellow gold. The style and method of construction suggest they were made in the early 20th century.

At first, we thought they might be for suspenders or lingerie straps. That didn’t exactly make sense. Women don’t often wear suspenders and the buckles are too heavy for lingerie. In researching the maker’s mark, one of our friends in the gemological community suggested they might be shoe buckles and sent over this image– Bingo. Not quite so fancy as our vintage buckles but you get the idea.

The buckles are designed for a strap that is ~ 1 3/8 inches wide. The rectangular opening in the clamp is where a strap attaches, then the other strap slides under and out. The clamp closes easily and the serrated edge insures a perfect fit and a secure grip.

The size of the buckles suggests a small foot, and the ornate style and  beautifully engraved initials suggest a gift– perhaps something special for the Debutantes’ Ball!

As always, our Estate Department offers many interesting treasures from the past. Stop by and shop or just enjoy browsing.. We’re open Tuesday thru Saturday, 10 to 5:30.

If you have jewelry you’d like to sell, we’re always open to buy. If you need appraisals or information about jewelry you own, our staff of gemologists are at your service with expert advice and information. We also offer consignment services for auctioning high value items. Call for an appointment.

For more information about appraisals, go to this page,

Mardon Wins 2017 Reader’s Choice

September 8th, 2017 by James L. Sweaney, CGA, FGA. GG

For the 9th year in a row, Mardon wins the Press Enterprise Reader’s Choice award! Last night, Kaye and I attended the PE Banquet & Awards Ceremony at the beautiful Riverside Convention Center. We saw familiar faces, met new winners, and the food was great! Congratulations to Gordon Bourns for the PE Community Service award– well deserved!

You’ll be able to see all the winners in the Best of Inland Empire supplement in Sunday’s Press Enterprise, and you can see it online at This will help you find the best shopping, dining, and services in the area.

We’d like to thank all of you, our loyal customers and patrons– you’ve stood by us over the years and helped us build our unique  business. Our mission is to provide outstanding merchandise and customer service to the Inland Empire– with your support, we’ll continue to grow and prosper.

Our new shop here at the Canyon Crest Towne Centre has been very well received by our customers– the store is open, comfortable and spacious, making it much easier for you to browse and shop. It’s easy to get to and has lots of free parking. Business has been very good so we’ve been able to add an employee – stop by and meet Stephanie Holcomb, our newest Mardon staff member.

While our business has based in Riverside since 1961, it’s been very gratifying to see folks coming to us from cities all over Riverside county, including Corona, Temecula, Murrieta, Lake Elsinore, Ontario, Redlands, Yucaipa, Desert Hot Springs, and others. We’re even drawing customers from San Diego, Orange County, and Los Angeles County, and of course, our website brings customer from all over the United States.

One of the things we’ve tried to do over the years is keep up with new technologies that help us do our work better and more efficiently. This year, we added the Ortery PhotoBench, a sophisticated system for photography and videos. Scott Christiansen, our Tech Wizard and Chief Science Officer has been very busy over the last few months –you can now see videos of our fine jewels here on the website.

Jenny Sweaney has been creating outstanding new one-of-a-kind jewels. Here’s a fabulous ring featuring a vintage carved intaglio Moonstone– a rare gemstone from bygone days.

Our Estate Department continues to grow, so you can find new pieces weekly. Our repair department is busy as always, but stands ready to repair or restore your jewelry with expertise and TLC. Our Appraisal Department stands ready to serve your needs, whether for written appraisals for insurance or estates or for verbal consultations so you’ll know the value of your jewelry. We’re open to buy most fine jewelry and precious metals – stop by for a quote.

Thanks again for the vote of confidence– we’ll keep working hard to deserve your trust and patronage. If you haven’t already been by the new shop, please visit us at Canyon Crest Towne Centre, on the center parking lot right next to the RiteAid drug store – Easy to find if you enter thru the Central Ave. entrance. We’re here Tuesday thru Saturday, 10 to 5:30. See you soon!


Annual Sale

August 31st, 2017 by James L. Sweaney, CGA, FGA. GG

It’s that time again! Mardon’s Fabulous Annual Clearance Sale is on! Beginning Friday, Sept. 1 thru Saturday, Sept. 9 we’re discounting our inventory of fine Mardon Originals, unique Estate pieces, and Designer Jewels. You can realize extra savings from 10 to 60% on fine merchandise and we can make way for new items in time for the holiday season.

Here’s a grand Estate ring, a lush statement piece of red garnets and 18K yellow gold, discounted from $895 to only $626.50 + sales tax– that’s a savings of almost $270!

I-26095 19 carats of Garnet & 18K Gold Ring

We have lots of beautiful estate engagement rings, from vintage to modern styles.

Here’s a sweet little Art Deco white gold engagement ring set with a sparkly Old European cut diamond weighing .28 ct. Perfect for the young couple just starting out. Was $495, will be just $346.50 + sales tax.

I-25985 .28 ct. Old European Cut Diamond in 14K Art Deco Ring

If your taste is more modern and you want a bigger diamond, how about this white gold ring set with a 3/4 ct Radiant Cut diamond, accented with 4/10 ct of sparkling round diamonds? Our everyday price is only $1995 for this ring with 1 1/5 cts of diamond – you’ll save ~ $500. The sale price be $1396.50 + sale tax

I-23515 .78 ct. Radiant Cut diamond center, .40 cts round diamonds, 14K white gold

We’re even discounting our magnificent Mardon originals. This One-of-a-Kind design by Jenny Sweaney features one of the most beautiful emerald cut natural pink sapphires you will see, 1 1/2 cts of perfect pink, accented with triangle blue sapphires, diamonds, and rose gold. Simply stunning!

The ring will be marked down from $4995 to $3496.50 + tax– save ~ $1500 on an stunning designer piece- wear it as an engagement ring that will draw attention and envy

I-25261 1.56 ct Pink Sapphire, 1.07 ct Blue Sapphires, .08 ct Diamonds in 14K Rose Gold.

The Sale is only once a year for one week, so hurry on down. We know it’s hot and muggy- we have air conditioning and the values will be worth it. Sale begins Friday, Sept. 1, ends Saturday, Sept. 9

Raincross items, Special Orders, Repairs, and Layaways are not included in the sale

The Mardon Way – Technology

May 30th, 2017 by James L. Sweaney, CGA, FGA. GG

Mardon has built its reputation as the best jeweler in the Inland Empire by creating its own way of doing business. The Mardon Way is to offer superior expert services along with distinctive merchandise in an information-rich atmosphere. In the old days, Mardon would have been known as a manufacturing jeweler. Today, we’ve added extra dimensions by using advanced technology to enhance our products and services. Our technology means we can offer unique jewelry and custom design services at very competitive prices.

Computer aided design (CAD) and modeling (CAM) gives us an efficient and flexible way to create original jewelry. We listen to your dreams, ideas and concepts and craft them into beautiful wearable jewelry using these highly efficient methods. Some stores that offer “custom” designs start from standardized design templates which are then tweaked just enough to be called custom. At Mardon, we design custom pieces from scratch. With few exceptions, our casting, setting and finishing is all done locally by the best craftsmen in town.

Pieces like wedding bands, medallions, pendants, and earrings that require precise detail  or that have relatively simple forms are made on our ModelMaster 1000 CNC Mill. This is a high precision lathe controlled numerically by computer instructions (CNC) that are generated by a computer aided design program (CAD).

ModelMaster Mill

ModelMaster CNC Mill

Other pieces that have more complex three dimensional forms are best made using our DigitalWax Rapid Protoype Machine, essentially a 3D printer. It uses a BluEdge laser to build a castable model out of plastic resins– the laser light moves back and forth to build the model in 5 micron layers. Wonderfully intricate and complex designs are now possible.

Rapid Protype

DigitalWax Rapid Prototype Machine

The newest addition to our arsenal of high tech is the Ortery 3D PhotoBench 60. This state-of-the-art imaging system is designed to take full advantage of the superb digital technology found in today’s cameras, including video and 3D imagery.We work diligently to illustrate the subjects of the Mardon blog faithfully– all part of our mission of honest representation and consumer education. We’re still learning, but in the coming months our new pieces will be shown in a new light!

We invest in these new technologies so that we can bring you the best product at the best prices. These tools are not cheap– the Model Master Milling system cost over $30,000 — but we’ve found that in the long run, they keep Mardon in the forefront as the Best Jeweler in the Inland Empire.

Voting for the Press Enterprise Reader’s Choice Survey ends Friday, June 2. Help us keep the streak going by voting Mardon — we’ve been voted Best Jeweler 9 years in a row.  Go back to our home page for easy access to the survey– one click and you’ll be ready to vote. It’s so easy and you don’t have to complete all the pages or categories. Best of all, you can vote more than once.

Thank you for your vote~ we promise to continue to strive to be the best!

Ortery Photo Bench

Ortery 3D PhotoBench 60

Ortery open

Ortery Photobench opened



The Mardon Way- Fine Gems

May 17th, 2017 by James L. Sweaney, CGA, FGA. GG

benoit pic for jim

Mardon has developed its reputation as a fine jeweler by creating its own way of doing business. The Mardon Way is based on our passion for fine colored gemstones. Because we love the richly colored treasures that Mother Nature has created for us, we’re dedicated to setting these fine colored gemstones into beautifully made pieces that are a pleasure to wear.

We sell beautiful gemstones you won’t see at typical jewelry stores. Of course, we offer fine Diamonds, Emeralds, Rubies, and Sapphires, but where else in our community can you buy such unusual jewels as Benitoite, our California state gem?

Benitoite Ring jpg

.75 ct. Benitoite in custom platinum ring by Mardon

Benitoite ring

.92 ct. Benitoite in custom platinum ring by Mardon

Or natural Alexandrites, with their dramatic color change?

Alex ring copy

Matched pairs of natural Alexandrites in custom ring by Mardon

Padparadscha Sapphires?

padparadscha custom ring

4.9 ct. natural Padparadscha Sapphire in platinum custom ring by Mardon

Paraiba type Tourmaline?

Mint tourm

2.56 ct. Paraiba like (Cuprian) Tourmaline in Mardon Original rose and white gold ring

Burma Spinel?

Spinel Filigree ring

2.43 ct. Burma Spinel in custon platinum & 18K ring by Mardon

Inperial Jade?

Art Deco Jadeite ring

14 ct. Imperial Jadeite cabochon in vintage Art Deco platinum ring

How about Gemstone sculptures by noted American lapidary artists like David Dyer?

zig zag ring 2

4.96 ct “Gypsy Rose” Garnet ZigZag Fantasy Cut by David Dyer in Mardon Original ring

We stock a wide variety of fine and unusual colored gems, ready to be set.


4.09 ct. Royal Blue Ceylon Moonstone


1.82 ct. Lightning Ridge Black Opal

Spessartine Garnet

11.56 ct. Spessartite Garnet

And where else will you find qualified Gemologists who can show you these pieces and tell their story? We have a Certified Gemologist Appraiser (AGS), a Certified Gemologist (AGS), and two Graduate Gemologists (GIA) on staff. We are members of both the American Gem Trade Association (AGTA) and the American Gem Society (AGS), professional organizations dedicated to consumer protection through education and fair dealing.

Our way of doing business is much riskier than the safe merchandising style you see in many jewelry stores, but it’s more rewarding for our customers and for our staff. Please come visit our new shop in the center of the Canyon Crest Towne Centre– it’s suite 14, next to the Rite Aid drug store. We’re here Tuesday thru Saturday, 10 to 5:30.

If you appreciate having a jeweler in your community who has the passion, expertise and resources to feature fine and unusual gems, please support us by by voting in for the Annual PE Readers Choice Survey, going on now. Just click the button on our homepage to go to the online ballot or you can vote by mail– ballots are published weekly in the Press Enterprise. And remind your friends and family– you can vote more than once! Your voice will be heard!


Amethyst Riviere Necklace

May 5th, 2017 by James L. Sweaney, CGA, FGA. GG
Riviere neck 1

175 carat Amethyst Riviere Necklace

Mardon has just acquired an exciting Victorian Amethyst Riviere Necklace. The antique Riviere necklace is a classic style much favored by Anna Wintour, famous editor-in-chief of Vogue magazine. Wintour is often seen wearing several antique Riviere necklaces at a time. Movie buffs recognize Ms. Wintour as the inspiration for the title role in “The Devil Wears Prada”, Miranda Priestly played by Meryl Streep.

Anna Wintour & Antique Riviere Necklaces

Anna Wintour & Antique Riviere Necklaces — Photo by Shankbone

This everlasting classic is comprised of gemstones of the same type that graduate smoothly in size. The gems are set in separate collet settings linked by small loops, so that the gems are featured prominently without excessive decoration.

Upper- Garnet collets in gold, Victorian, Lower - Amethyst collets in silver, Georgian

Upper- Garnet collets in gold, Victorian, Lower – Amethyst collets in silver, Georgian

 Collets are challenging to make. A band of metal is fitted tightly around the gem, with the top edge bent onto the stone as in a bezel. Excess metal is filed away at the edge of the gem to leave small prongs holding the stone– difficult to achieve without damaging the stone.

Amethyst and Citrine were most often used– these Quartz gems are relatively abundant so matching suites of large stones were easy to assemble. Rivieres became popular during the Georgian Period, 1714 – 1837, and were all the rage in the late Victorian period, 1880 – 1900.

Our necklace is a true antique, probably made circa 1870 – 1880. The collets test to be ~ 9 – 10 K gold. There is some variation in the collets, so we think this piece is what in known in estate jewelry as a “marriage”. Marriages are accepted in antique jewelry because of their age– our necklace is a true antique, probably made circa 1880, about 140 years old or more.  During the long history of the piece, who knows what transpired– the important thing is whether the integrity of the piece has been retained. Some of the collets could have been made during  the earlier Georgian period, prior to 1837. Here we have similar collets and similar gems, so we’re confident in offering the necklace as correct for the period.

The Amethysts range from 21 carats at the center to just under 4 carats each at the clasp. Some are grading into Ametrine, with both purple and a bit of gold color showing. The total gem weight for this necklace is estimated to be ~ 175 carats.

Because of the popularity of this scarce item, we’ve seen Amethyst Riviere Necklaces with similar sized Amethysts being offered for as much as $20,000. For example, you can go to this link to the S.J Philips of London website, /necklaces-other where several Rivieres are shown. Because we think ours is a marriage, we’re offering this piece at the bargain price of $4750.

Mardon offers the best and most exciting pieces of estate jewelry to be found in the Inland Empire, as well as fine original works, built-from-scratch custom jewelry, and the full services a real jeweler can offer.

Don’t forget to vote in the Annual Press Enterprise Reader’s Choice– we’d love to be your choice as the Best Jeweler in the Inland Empire for the 10th year in a row.

2017 Best of IE



Reader’s Choice Voting Starts May 1

April 29th, 2017 by James L. Sweaney, CGA, FGA. GG
I-26100 Zircon Star

Magnificent Cinnamon Zircon & Diamond Star Ring by Jenny Sweaney

It’s that time of the year again– the Annual Press-Enterprise Reader’s Choice Survey starts Monday, May 1. Readers of the Press-Enterprise will have a chance to choose their favorite businesses and services. It’s easy and fun to name your favorite shops, restaurants and entertainment venues. Reader’s Choice helps your favorites survive in today’s hyper-competitive business world, so your vote means something. You can vote online from May 1 to June 2.

2017 Best of IE

Our fans have chosen Mardon Jewelers as the Best Jeweler in the Inland Empire for eight years in a row! Your vote is important because it informs our community about the best choices for shopping, dining, entertainment and services. We sincerely say “Thank You!” and ask for you to vote for us again.

As many of you know, Mardon has a new location. After 20 years at the Mission Inn, we’ve moved to the locally owned Canyon Crest Towne Centre. And it’s been a happy move– our spacious new shop has a fresh and open ambiance. Our customers love the convenient restaurants, shops and businesses and especially the central location and easy parking.

Along with a dynamic new Showroom, we now have a roomy Workshop where you can see us make the magic happen, a Gem Lab & Consultation Room for privacy in buying and selling, as well as a handicapped accessible restroom.

Mardon continues to provide the wide range of beautiful handcrafted and estate jewelry and the expert services you’ve come to expect. In the coming weeks, we’ll feature new finds and creations and discuss in detail the important services we offer, so check back often. ( better yet- subscribe! – you’ll be automatically notified of new posts ). And don’t forget to Vote!

Mardon — Your Family Jeweler Since 1961

    Member - American Gem Society Member - American Gem Trade Association Polygon - The Jewelers Information Highway Harmony Recycled Precious Metals Firemark Diamonds