Many Hats of Me: Gem Setting Challenges When Designing Jewelry with Native Cut Stones

Saturday, April 27, 2013

Gem Setting Challenges When Designing Jewelry with Native Cut Stones

Native Cut VS. Calibrated Gemstones

Most of my gemstones are purchased from eBay stores from Chanthaburi, Thailand, an area famous for its gem trading. I buy all sizes, shapes, and types; most are purchased for under $50.  Although beautiful, these stones are "native" cut stones: uncalibrated, hand-cut stones, that do not fit standard settings.

Native cut Kunzite, Citrine, and Amethyst. 
Notice the "window" in the Citrine, an undesired quality in gemstones.

Calibrated Gems

Calibrated gems are cut by either hand or machine that follow the acceptable standard sizes that most jewelry manufacturers use.

Standard size gem chart

Native cut stones are often cut to maximize the weight of the stone. Consequently, they are often cut "too deep" to fit into standard settings.

Parts of a Gemstone

parts of a gemstone

Ideal Proportions of a Gemstone 

  • Crown: 1/4 to 1/3 overall height
  • Girdle: 2% overall height
  • Table: 40% to 70% overall width
  • Pavilion: 2/3 to 3/4 overall height

Trying to Set a 5mm Round "Native-cut" Spessartite Garnet

I made an Argentium silver ring this week using thin, relatively inexpensive wire to test out a new design. 

Argentium silver is a type of sterling silver that does not tarnish easily since it contains more Germanium in its alloy. It's slightly more expensive than standard sterling and it has a lower melting point.

wirework argentium silver ring

I was planning to solder an inexpensive Argentium silver 5mm Snap-Set setting I purchased from Rio Grande, but as you can see, my 5mm "Native-cut" Spessartite Garnet did not fit the setting at all.

5mm Argentium Snap-Set settings

5mm orange spessartite garnets

5mm native cut Spessartite garnets

5mm round Spessartite garnet in 5mm Snap-Set setting

The Snap-Set settings are manufactured with a very thin (small gauge) metal that deforms easily. My stone, although exactly 5mm in diameter, has a pavilion that bulges out, causing the stone to pop out of the setting.

I will reserve my Snap-Set settings for cheap calibrated CZ (cubic zirconia) stones whose loss (from a failed setting) will not break my heart. 

Settings for Native or Non-calibrated Gemstones

After weeks of searching on and offline, I found a few suppliers that offered settings that may accommodate my gemstones. I will be testing these settings in a week when they arrive in the mail. 

Tripps Manufacturing

Tripps Manufacturing, located in Socorro, New Mexico, is a 40-year-old company that sells jewelry findings and tools. Their website is not organized well and their search engine needs an update. HOWEVER, this store sells hard to find items at great prices. I suggest that you spend a few days looking at every category carefully so that you don't miss out on an much sought after item. 

I purchased a variety of settings to see if they would fit my irregular and deep cut stones. These settings are pre-notched so they should be easier to set. My hope is that the prongs are long enough to accommodate the higher crown, thicker girdles, and deeper cuts. 

9mm round red zircon gemstone

I hope my 9mm native cut Zircon fits!!

Settings for Tourmalines and Any Long and Heavy Emerald Cut Stone

I purchased a large green tourmaline for my sister and took it to a local jeweler to set. They were unable to find me a setting for the stone and were estimating a custom setting for at least $250! Luckily, Tripps carries a special "Tourmaline" setting that can accommodate both a deep cut and long rectangular stones. It arrives in a week!

Rio Grande

Rio Grande is 70+ year old company that is also headquartered in New Mexico, but in Albuquerque. This large, family-run company was recently purchased by a Richline, a Berkshire Hatheway company, indicating to me, that it is a well-run and profitable company. I purchase my Argentium silver stock and gold stock at Rio Grande, since their prices are low, even compared to metal refineries, such as Ross Metals, and G&S Metals. Rio Grande is also one of the few places to find Argentium silver. 

However, Rio Grande carries a limited range of metals and findings. Metal refineries and stores that cater to jewelry professionals, such as Otto Frei, and Stuller, Ross Metals, and G&S Metals offer a wider variety of metal types and sizes and jewelry settings. To access some of these stores, you will need a business license. 

Rio Grande's Lever-Set Setting

Rio Grande advertises a new kind of setting, called the Lever-Set, that can be easily set with a pair of jewelry pliers. They also claim that their settings can take a variety of different sized stones, including deep cut stones. Looking at the deep "V" shape of the setting, I am very hopeful that this setting will work with my stones. Can't wait to try them out!

Custom-made Gemstone Settings

I have attempted to fabricate a wire-wrap settings for some of my large oddball gems. Last summer, I created a wire-wrap setting for a very large checkerboard-cut Amethyst. Wire-wrap settings are well-suited for very large (10 karats+) and bulky gemstones.

Pear-shaped Amethyst pendant custom set with Argentium wire

Pear-shaped Amethyst pendant custom set with Argentium wire

I used 22 gage Argentium square wire, and 20 gauge half-round wire to make this setting. 

Smaller stones can only be set with a more traditional prong setting. My project this summer is to learn how to fabricate prong settings by soldering together jump rings and half-round wire. 

I've put together the following list of wirework and metal clay books and tools that I have in my library or used personally. Thanks for reading!

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