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.

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”.

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

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

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.

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.

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.

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.

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.

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.

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