Category: gemstone cutter

Quartz-So Common and yet so Special

Flawless Quartz Crystal Sphere at the Smithsonian Natural History Museum (106.75 lbs)

Flawless Quartz Crystal Sphere at the Smithsonian Natural History Museum (106.75 lbs)

This crystal sphere is the largest cut piece of  flawless quartz in the world, weighing in at 242,323 carats!  It symbolizes our fascination with something so beautiful and yet so common.  Quartz is found around the world, in large quantities, and is considered one of the most common minerals on Earth.  It’s found in sand, dirt, and dust.  Yet, when fashioned by gem cutters and put in a stunning piece of jewelry, it can be breathtaking.

Quartz is a complicated gemstone.  One of the reasons it’s tricky is because the term “quartz” is used for varieties of gems, as well as for a species of gem and as a group of gems.  So, for example, Rose Quartz is a variety of the species Quartz.  So is Citrine, Amethyst, and Tiger’s Eye!  All these varieties, and others that are couched under the species of Chalcedony, such as Agate and Jasper, are considered to be members of the group, Quartz.  Very confusing!!

Perhaps it’s best to start with the fact that mineralogists and geologists see any mineral with the chemical makeup of silicon dioxide, SiO2, as Quartz.  Regardless of whether the crystals making up that stone are large, small, or microscopic, it’s all Quartz.  Gemologists, on the other hand, separate the gems into those whose crystals are larger and those too small to see without a high-powered microscope.  Those with larger crystals are called Quartz and those with microcrystalline structures are labeled Chalcedony.

Under these two species are many varieties that are used in jewelry.  Probably the most commonly known variety of the quartz species is Amethyst.  That regal purple has been admired for centuries.  The purple color comes from natural irradiation acting upon a trace element of iron.  The saturated, medium to deep reddish purple is the most prized color, but amethyst ranges from a light, pinkish purple to that deep purple hue.  Amethyst is not rare, but the prized color is more rare because usually only the tips of the amethyst crystals have that depth of color.

Agate and Amethyst, showing the deep purple tips of the quartz crystals, as well as the microcrystalline Agate, which is part of the Chalcedony species.

Agate and Amethyst, showing the deep purple tips of the quartz crystals, as well as the microcrystalline Agate, which is part of the Chalcedony species.

Other varieties of the Quartz species include Citrine, the orange-yellow gemstone that’s November’s birthstone, and Rock Crystal, which is colorless because it has no trace elements.  There’s also Rose Quartz, Smoky Quartz, Prasiolite (aka Green Amethyst), and Ametrine (a bi-colored gem combining the purple of Amethyst and the yellow of Citrine).

Members the Chalcedony species have been used in jewelry even longer than Amethyst!  Agates, which exhibit wavy bands of color, were used in amulets and talismans over 3000 years ago.  They were also used to make cameos.  Carvers would reveal a differently colored band by carving down around the subject of the piece.  Today you’ll see agate slice pendants that are sometimes dyed to accentuate the banding.

Probably the most valuable member of the Chalcedony species is Chrysoprase.  This translucent gemstone is beloved for its natural apple-green color.  It owes its color to the presence of  nickel.  A big discovery of Chrysoprase was made in 1965 in Australia.  Because its color can resemble fine jadeite, it’s sometimes called “Australian Jade.”

Chrysoprase cabochon

Chrysoprase cabochon

Other varieties of the Chalcedony species include Black Onyx (dyed black chalcedony), Carnelian, Jasper, and Fire Agate.  Most chalcedony is translucent to opaque, so it’s rarely faceted.  Most often it’s fashioned into beads, slices or cabochons.  But, just like all Quartz, it registers a 7 on the Mohs Hardness Scale, making it a good choice for rings and bracelets as well as earrings and pendants.

There’s so much that can be said about this beautiful mineral that surrounds us everyday.  But I want to end with the sentiment– “How wonderful when something so common can also be so special!”

Custom-made Ametrine Ring in our showcase!

Custom-made Ametrine Ring in our showcase!

 

Understanding Gemstone Treatments

| February 25, 2016 | Reply
Paraiba tourmalines photographed from the GIA Collection for the CIBJO project from the Dr. Eduard J. Gubelin Collection.

Paraiba tourmalines photographed from the GIA Collection for the CIBJO project from the Dr. Eduard J. Gubelin Collection.

This blog is the first of a series on gemstone treatments.  The truth is, all gemstones have been modified by man.  We’d like to think that a gemstone’s beauty is completely natural, but the reality is man plays a part.  Cutting and polishing bring out the sparkle and color.  Shaping and setting is all done by man.  So a gemstone’s beauty can be attributed to both man and nature.  Each consumer must decide what level of man’s contribution is acceptable.  Everyone sees that man must be involved to some degree, but opinions vary on enhancements such as irradiation, dyeing, or fracture-filling.  Is there a point where man’s contribution to a gemstone’s beauty goes over the fine line, when the stone just doesn’t seem natural anymore?

Another fine line is the one jewelers walk everyday when conversing with customers about gemstones.  There are laws and guidelines, set by the government and the AGTA (American Gem Trade Association), for disclosure of gemstone treatments.  But jewelers adhering to those guidelines also have to make sales in order to stay in business.  Some customers are truly interested in learning about how gemstones arrive at their beautiful state.  But many would be bored by a lesson in gemstone treatments and might walk away from a sales representative who insisted on giving all the details.  Certainly anyone who sells jewelry should honestly answer customer questions about gemstone enhancements or treatments.  We want our customers to understand as much as they’d like to understand about gemstone treatments.  We want them to understand that, if treatments didn’t exist, most of us would be unable to afford pretty gemstones.

So that’s what the series will be about.  It will give you an overview of some of the main treatments on some of the most common gemstones in the market.  The series will also discuss some gemstones that are not treated–ONLY cut, polished, and set.  If you find this fascinating, I will include some sources for learning more.  And remember, if you want to know more about the gemstone you’re buying, just ask.

The Story of Campbellite

campbellite

I’ve lived most of my life in Michigan and my maiden name is Campbell.  Most people don’t know that because I’ve been married so long!  But I always thought Campbell was a good name, so I was both happy and surprised to learn that there is a gemstone named after. . .no, not me, nor my kinfolk, but after the Campbell shaft of the well known Bisbee Mine in Southern Arizona.

So, what’s the story of Campbellite?  As explained by one of the stone cutters at Arizona Lapidary, Campbellite is an uncertain  mixture of minerals like cuprite, azurite, malachite, calcite,chrysocolla, pyrite, quartz, and copper.  Its color and look varies because there’s no set amount of these minerals.  It was first discovered by miners looking for copper.  The bosses weren’t interested in this unusual rock, and told the miners to discard it.  But the miners had a different plan.  They saw its beauty.  So, yes, they dumped the Campbellite in the trashcan.  But they separated it carefully from the real trash.  And when no one was looking, they loaded the discarded gem into the back ends of pickups.  Campbellite has been showing up in the market, piece by piece.  There’s not a lot of it–I’m sure plenty WAS dumped.  The mine closed in 1975, and there is no other known source of Campbellite.  But I bought one piece of it, cut into a smooth cabochon, and plan to make a bolo tie for my dad.

I learned a little bit about the mine shaft itself.  It was first developed in 1927, originally as a way to get oxygen to other parts of the Bisbee Mine.  But soon it was one of the best producers of copper ore, with yields of 8-10% copper.

Finally, who is the Campbell shaft named after?  A little research revealed an amazing coincidence.  The shaft was named after Gordon R. Campbell, who actually lived and went to school in Michigan!  He graduated from U of M in 1893 and was a mining executive and lawyer up in the Keweenaw Peninsula.  The Keweenaw Peninsula, jutting from the Upper Peninsula of Michigan, is one of the best known sources of copper world-wide.   Towns like Calumet, Houghton, and Copper Harbor were booming back in the mid-1800s because of copper.  Anyway, Gordon Campbell helped form the Calumet and Arizona Mining Company in 1901, serving as the company’s President from 1921-1931.   It was this company that operated the Bisbee Mine.  So Campbellite WAS named for a Campbell living in Michigan.  Who knows?  Maybe he’s a long, lost cousin?

The Campbell shaft, courtesy of the Arizona Historical Society

The Campbell shaft, courtesy of the Arizona Historical Society

 

 

 

 

 

 

The Beauty of the Lazare Diamond

| November 10, 2015 | Reply

diamond

Perhaps you’ve seen the phrase, “Lazare. . .the World’s Most Beautiful Diamond.”  Your mind might question the assertion.  After all, aren’t all diamonds beautiful?  How can a company make this claim?

The answer lies in the cut.  In 1919, the cousin of founder, Lazare Kaplan, developed a mathematical thesis for cutting diamonds to precise angles and proportions to gain the optimum reflection and refraction of light.  When a diamond is ideally cut, light rays from all sides are bent towards the center of the diamond and are reflected back through the top.  If not ideally cut, light will “leak out” through the sides or bottom of the diamond.  The beauty of a colorless diamond is all about its brilliance, scintillation, and fire.  The Lazare Ideal cut maximizes all three.

diamond-cut-chart

A beautiful diamond is also tied to a company that does good work in its community.  Lazare Kaplan International, Inc. supports a number of important causes in Namibia, where most of its diamonds are mined.  LKI also supports policies that

  1. protect fundamental human rights and the dignity of the individual

  2. prohibit the trade in conflict diamonds (zero tolerance policy for conflict diamonds and strictly adheres to all protocols of the Kimberly Process)

  3. prevent money laundering and combat the financing of terrorism

  4. ensure business is conducted in an environmentally responsible manner

Finally, a beautiful diamond is one that can be yours forever.  Every Lazare diamond of 0.18 carats and higher has the Lazare logo and an individual identification number, laser inscribed on the diamond’s girdle.   This logo is your proof of authenticity as an ideal cut Lazare diamond, and the identification number is your proof of ownership.

Lazare Kaplan International, Inc. has been in business since 1903.  It plans to be around for a long time to come.  When it’s your turn to look for the world’s most beautiful diamond, be sure to remember Lazare.

Lazare Diamond Rings in Michigan

 

What’s a Gemstone Roundtable? Would I want to go to one?

If you love gemstones, ask your jeweler if he/she hosts roundtable events.  These are usually evening events that last 2 – 3 hours, taking place after your jewelry store closes.  Food and drink are often served, and you are introduced to a gemstone expert.  This expert shares knowledge and stories about gemstones and the gemstone industry.  Sitting at a, usually rectangular, table, guests are given the chance to see, touch, and dib on approximately 100 different gemstones.  Dibbing simply means that you would like another look at that gemstone after it has gone around the table.  These gemstones are for sale, but there is never an obligation to buy.  The goal is to have fun learning about and playing with gemstones.

More people want to be involved in the making of their jewelry.  Mountings can mask flaws of gemstones, so it’s to the buyer’s advantage to see gemstones un-mounted.  And mountings can be unique if you work with a custom designer.  On-staff designers are generally at the roundtable event and they can help you with ideas for any gemstone you select for purchase.  The whole process of 1) picking out the gemstone; 2) deciding on a design; and 3) having the piece made by your local jeweler is a memorable one.

Dearborn Jewelers recently hosted a roundtable event with gemstone dealer, Judith Whitehead.  Our next event will be in September.  If you are interested in attending, give us a call and we can put you on the list.  It promises to be a great time.

roundtable1roundtable2