Alexandrite Impersonator

June 6th, 2015 by James L. Sweaney, CGA, FGA. GG
Alex Ring

Natural Alexandrites & Diamonds in 18K white gold


Alexandrite is a very rare and valuable natural gemstone, famous because its color changes almost magically, from red to green. Alexandrite is a variety of Chrysoberyl, a mineral found in nature. Chrysoberyl is well suited for jewelry because it is very hard and durable, and because it’s rare, beautiful and unusual. The colors we see in a natural Alexandrite is usually a green to bluish-green when viewed in daylight, a red to reddish purple when viewed in incandescent light.

The mystique of Alexandrite begins with it’s name– as the popular but controversial story goes, Alexandrite was discovered on the tsarevitch Alexander’s sixteenth birthday, April 17, 1834 and named in his honor. The facts differ from this romantic tale, but the true story will probably be never known. Alexandrites quickly became a sensation because of their color changing property and their association with Russian royalty.

Around 1890 or so, using a method called the Verneuil process, chemists began producing a crystalline material that exhibited a strong color change like the Alexandrite, from reddish purple to blue green. This material is an oxide of aluminum known as Corundum. Pure corundum is colorless but can have different colors when impurities are present. Corundum is known as Ruby if red, Padparadscha if pink-orange, Sapphire for all other colors.

Syn. Sapp R-P small

Synthetic Sapphire in Incandescent Light

Syn. Sapp b-g small

Synthetic Sapphire in Daylight

Man-made Corundum is referred to as synthetic sapphire or synthetic ruby, depending on its color. Vanadium is added to the melt to create the color change sapphire. The manufactured material with color change is properly known as synthetic color change sapphire, synthetic alexandrite-like sapphire or synthetic sapphire with alexandrite-like color change.

The color change in both natural Alexandrites and synthetic color change sapphires depends on the color temperature (Kelvin) of the light in which you view the stone. The stones strongly absorb light in the yellow section of the color spectrum. Daylight is lower in the color spectrum, so blues and greens will come thru. Artificial light, like candlelight and other incandescent lights, will emphasize the warmer end of the visible light spectrum, so you’ll see the reds.

Synthetic color change sapphire became enormously popular because of it’s interesting colors, great wearing qualities, and very low price. Synthetic corundums are manufactured inexpensively to this day by the same Verneuil method used in the 1890’s. We still see this material used as in class rings, costume jewelry, and as an alternate June birthstone for the true natural alexandrite.

Sadly, many people who own these synthetic color change sapphires are under the impression they are valuable natural Alexandrites. Because they’re inexpensively mass produced, synthetic sapphires with alexandrite-like color change are very cheap– a 2 carat stone might retail for $30, while a 2 carat fine natural Alexandrite might sell for $30,000! You can see why a person might be very excited if they have a large stone, thinking it’s genuine Alexandrite.

A worse problem is that synthetic color change sapphires are often sold as Alexandrite. Sometimes, it’s because the seller doesn’t know the difference, sometimes it’s with intent to defraud. Either way, it shows how important it is to deal with someone who is knowledgeable and ethical.

Synthetic color change corundum is easy for a gemologist to identify. The Verneuil process leaves visual traces that prove how the stone was made. The material is grown in a carrot shaped mass known a boule. The rounded form leaves curved growth lines within the stone known as curved striae. These may appear as straight lines, but careful examination will prove them to be slightly curved. Once you see the curved striae in a doubly refractive material, you’ve proven it to be synthetic corundum.

Striae 2_edited-2

Curved growth lines in synthetic color change sapphire

At Mardon, four gemologists including a Certified Gemologist Appraiser are on staff to identify and value gemstones and jewelry you have questions about. We also buy estate jewelry. The fees for our gemological services are modest, and the knowledge you’ll gain can be quite valuable. Stop by our shop Tuesday thru Saturday, 10 to 5:30– we’re alway interested in seeing your jewelry and hearing the stories that go with your pieces.


A Good Jeweler is Hard to Find

June 2nd, 2015 by James L. Sweaney, CGA, FGA. GG

We recently performed extensive repairs on a wedding ring that had been purchased in the LA Jewelry Mart. Thing is– the ring was brand new!

The client brought the ring to us for an insurance appraisal. We recognized this as a “jewelry mart special” because he had a “feel good appraisal” from the original seller that valued the ring at about 3 times what he had paid.

Two serious problems became apparent when we inspected the ring. First and foremost, the center diamond was ready to fall out! It was the worst job of setting a diamond this writer has seen in over 40 years in the jewelry business.

Poor Setting top_edited-1

When properly done, the prongs in a tiffany style head (the 6 prong setting) are fitted to the stone and tightly crimped over the edge of the diamond so they grip the stone securely. In this instance, three prongs on one side of the diamond weren’t gripping the edge of the stone at all, and the diamond was seriously tilted.

These two side views show how poorly the stone is set– it’s tilted, the seats don’t fit the stone and the prongs aren’t set onto the stone .

Poor Setting side 1 Poor Setting 2

The most likely explanation for the slipshod work is that the jeweler sold the stone separately from the ring, and the head in the ring was for a smaller diamond. Not wanting to  spend the money to replace it with a proper sized head, the seller made the decision to force the big diamond into the small head– and succeeded long enough to get the ring out the door.

After consulting with our diamond setter, it was obvious the best course would be to replace the original head with one that would fit the diamond and to set the stone properly. At $200, not an inexpensive repair, but considering the diamond was valued at ~$7000, cheap insurance.

We also noticed that most of the channel set diamonds were loose and the bars between the diamonds were uneven and poorly polished– the result of hurried work and/or poor technique. Our craftsmen were able to tighten the diamonds and correct the uneven look– but so many stones were loose, it took a lot of time, resulting in a repair that cost another $200. In the end we were able to deliver a properly set and properly finished ring.

Repaired ring

The moral of the story is simple– you get what you pay for. The main reason for poor jewelry work like this is simple economics– quality work takes longer and requires more skill, so it costs more! Shortcuts and cheap labor are how some firms compete in today’s tough economy.

At Mardon, we take pride in our work. We make sure all of our original jewelry, custom designs, jewelry repairs and appraisals are done the right way. Maybe that’s why we’ve been voted Best Jeweler in the Press Enterprise Reader’s Choice for five years in a row.

Reader’s Choice voting has been extended to June 7– Vote for your favorite shops, restaurants, and entertainment venues by clicking on the red “Best of Inland Empire 2015″ on our home page, We’d appreciate your vote so we can keep up the good work!

Poor Setting side 2

Jewelry Auctions & 2015 Reader’s Choice Voting

May 22nd, 2015 by James L. Sweaney, CGA, FGA. GG


Mardon has placed a rare vintage watch for a client in this upcoming Important Watch Auction held at Sotheby’s New York venue. It’s Lot # 163, page 136 – you can browse the catalog at this URL,

This last year, we’ve added Jewelry Auctions to the list of services available through our extensive network of experts and colleagues. Many of our clients have expensive jewelry items they wish to sell for various reasons– for example, they have an inheritance that needs to be divided, they have pieces no longer worn or they simple want to raise cash. While Mardon buys all types of fine jewelry for cash, sometimes a high end item can only be properly valued thru an active market like auctions.

Auctions can be intimidating, especially to a person with no experience selling thru an auction. Auction houses charge fees for shipping, insurance, publication and promotion, and a commission based on the hammer price. Mardon has connections with such fine auctioneers as Sotheby’s and Christie’s. We can sell your jewelry through the appropriate auction for fees similar to what you would pay if you did all the work of estimating, shipping and insuring yourself. We’ll help you decide if selling your pieces thru an auction is the appropriate choice. No worries, no trips out of town, and you’ll be dealing with a local business established in our community since 1961.

Just a friendly reminder – Voting in the 2015 Reader’s Choice survey ends soon. If you’d like to be counted, it’s easy to do– just click on the red banner on the Mardon Jewelers Home Page,, — it will take you right to the Press Enterprise online ballot. You don’t have to complete all the categories, just the ones you want. It only takes a bit of time and you’ll enjoy giving recognition to the restaurants, shops, and entertainment venues that are important to your life.

So, please, check out the ballot in the Wednesday and Sunday Press Enterprise– look for Best of Inland Empire 2015. Better yet, vote on line at

We hope you’ll send a little love our way –  We work hard to bring you the very best in jewelry and to provide the expert services you need. We depend on your support and patronage to sustain our very small business. Thank you

Emerald Show Going On Now

May 5th, 2015 by James L. Sweaney, CGA, FGA. GG

Now showing- a Stellar Collection of Emerald Jewelry from our good friends at AG Gems. If you’ve ever wanted to see what an outstanding Natural Emerald looks like, this your chance. Stop by our shop – we’ll show you beautiful rings, earrings and a fabulous necklace, set with fine Emeralds from Colombia and  Zambia. These items have gemological certifications from GIA or AGL, so you’ll know for certain what the gemstone is.

Em Neck 2


Colombia is the most well known source of fine emeralds. The fabulous Muzo Mine of Colombia dates back to the time of the Spanish Conquistadores and before. At their best, Muzo Emeralds can show the classic slightly bluish soft green color for which emeralds are famous. Our 5.88 ct. gem is the perfect emerald color, and comes with an AGL certification.

I-23910 3:4

Magnificent 5.88 ct Muzo Emerald


3.47 Zambian Em, .81 d ring

3.47 ct. Zambian Emerald

This beautiful 3 stone ring centers on a stunning 3.47 ct. oval Emerald from Zambia, flanked by a matched pair of half moon shaped diamonds. The earrings feature 3 matched pairs of Zambian stones. Zambian emeralds are known for their deep color and excellent clarity.


7.19 ct em earrings

Zamibian Emeralds total 7.19 cts

Stop by and chat with our gemologists– we love show and tell, especially with extra fine gems. These items have gemological certifications from GIA or AGL– You’ll see the difference quality makes and we’ll explain the factors that make fine Emeralds one of the most sought after of all  gems.

We’re open Tuesday thru Saturday, 10 am to 5:30 pm.


Reader’s Choice 2015

May 2nd, 2015 by James L. Sweaney, CGA, FGA. GG

The annual Press Enterprise 2015 Reader’s Choice voting is going on now! Balloting lasts May 1 to May 31. It’s easy and fun to name your favorite shops, restaurants and entertainment venues. Your vote is important because it informs our community about the best choices  for shopping, entertainment and services. To vote online, go to

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Award Winning Gemcutters at Mardon

February 19th, 2015 by James L. Sweaney, CGA, FGA. GG

Mardon Jewelers has a new relationship with two of America’s finest gem cutters, John Dyer and David Brackna. We met both of these award winning artists at this year’s Tuscon Gem show and were able to purchase fine examples of their work.  We’ll soon be showing these wonderful gemstones in our unique Mardon Original Jewelry.

John Dyer is a master gemstone cutter known worldwide for his artistic creations and his passion for precision. He’s won 37 AGTA Cutting Edge Awards including 9 first place prizes. John’s work is truly exciting and his taste and selection of materials are wonderful. Each of his gems is etched with his logo so you’ll know it’s a genuine Dyber gemstone. You can visit his website to see a catalog of his work.

I-24741 Gypsy Rose Garnet Face 2

I-24741 Zig Zag Cut 1.96 ct Gypsy Rose Garnet

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Black Friday Diamond Deals

January 8th, 2015 by James L. Sweaney, CGA, FGA. GG

AGS logo

As members of the American Gem Society, we at Mardon Jewelers are committed to conducting our business ethically. Key tenets of the AGS are that the ethical business person never knowingly misrepresents the facts or intentionally deceives other parties. From our AGS Membership Manual, these are the first 3 of 15 specifically prohibited business practices.

1. Advertising which in any way is not the truth or has the intent to be misleading. 

2. Following a policy of regularly selling merchandise at prices lower than those at which it is marked or conducting repeated discount sales and discount promotional events as an on-going policy. 

3. Advertising or setting artificially high prices as the “regular price” to allow either a fictitious sale price or supposed discount “mark down” lower than the original price. 

Not only are we committed to fair pricing and ethical business practices, we’re also dedicated to consumer protection and education. One of the main reasons we decided to invest our time and energy publishing this blog is to offer our readers and clients quality information about both the good and the bad in our industry.

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Antique Jewelry Stars In Costume Drama

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

Antique splendor

We had a visit from one of our favorite clients, Chris, his wife Jaybee, and friends, on their way to a special event celebrating the Riverside Dickens Festival. We were pleased to see Jaybee wearing the exquisite antique necklace Chris recently acquired from Mardon. This necklace is one of the finest examples of Edwardian jewelry it’s been our pleasure to offer.

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EGL Graded Diamonds– Banned from Polygon and Rapnet

September 20th, 2014 by James L. Sweaney, CGA, FGA. GG

The Polygon Trading Network, an online buying/selling service for the diamond trade, announced the latest bombshell in the EGL Diamond Grading scandal. They will no longer list diamonds with European Gemological Laboratory International (EGL) reports. This follows in the wake of the decision by another trading network, RapNet, to ban all EGL report for it’s network.

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Readers Choice Best Jeweler 2014- Mardon!

September 6th, 2014 by James L. Sweaney, CGA, FGA. GG

We’d like to thank our loyal customers for choosing us for the sixth year in a row as the Press Enterprise Reader’s Choice Best Jeweler. We truly appreciate your votes and your confidence in our small but mighty enterprise. The annual Reader’s Choice supplement will be published in tomorrow’s Sunday Press Enterprise. Read the rest of this entry »

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