Category: gemstone jewelry

My Tourmaline

In 1890 an author named Saxe Holm wrote a charming story entitled, My Tourmaline.  The young heroine possesses a crystal of tourmaline, which she finds in the roots of a large tree.  It brings her good fortune until she loses it.  Bereft until she finally finds it in someone else’s collection, she and her tourmaline are eventually re-united and live “happily ever after.”  

What is it about tourmaline that makes people feel so connected to it?  One reason is because of all the colors it comes in.  There is no other mineral that comes in as many hues.  This rainbow quality translates to a lightness and happiness that appeals to all.  It also suggests tolerance, flexibility and a compassionate understanding.  The Sri Lankans named the gem, “turamali”, meaning a stone of mixed colors.  

A rainbow of gemstones, all of them are tourmaline.

Another quality of tourmaline is its pyroelectricity.  If heated, it actually has magnetic properties.  As a result, the mineral has many industrial uses.  You can find it in hairdryers to calm static hair, in joint wraps to promote blood circulation, and in tuning circuits for conducting TV and radio frequencies.  In the metaphysical world, tourmaline is seen as a strong protector, reflecting negativity away from anyone possessing the stone.  It’s also seen as a grounding stone that promotes a sense of power and self-confidence.  

Finally, tourmaline is a popular gemstone, featured prominently as the birthstone for October and the anniversary stone for the 8th and 38th anniversaries.   It has a hardness of 7 – 7.5 on the Mohs scale, so it’s durable enough to be set in rings.  It’s not as expensive as ruby, emerald, or sapphire, but it can sometimes mimic these colors.  And it’s mined on almost every continent– from the state of Maine to the island of Madagascar.  

You may own a tourmaline and not even know it, because the gem has so many trade names.  If you own a rubellite, an indicolite, a verdelite, a siberite, an achroite, or a paraiba, you actually own a tourmaline. You may also have a bi-colored or parti-colored tourmaline, a watermelon tourmaline, or even tourmalinated quartz!  There are so many different looks to this versatile mineral.  If these pictures are motivating you to own a tourmaline (or a second one), stop in our store.  We’d be happy to introduce you to the ones in our showcase.

Parti-colored tourmaline

Watermelon tourmaline earrings with rubellite and green tourmaline: custom-made by our benchjewelers

 

Tourmalinated Quartz: The black crystals are the tourmaline, also called schorl.

 

 

 

 

 

 

 

Watermelon tourmaline, carved into butterfly wings, and made into a pendant by our benchjewelers

The Michigan Gemstone

A large polished piece of Greenstone

A large polished piece of Greenstone

In late September I was in Swede’s, the famous light blue jewelry and rock store in the middle of Copper Harbor, Michigan.  The feisty woman in charge, 83-year-old Mary Billings, asked me as I walked in–“What is the gemstone of Michigan?”

When I answered, “Isle Royale Greenstone,” she looked at me with new respect.

“You’re only the thirteenth customer this season who has answered that question correctly.  And we’ve had a lot of people who’ve  walked through that door.”  She shook her head, a little disgusted that Michiganders weren’t commonly aware of their state gemstone.

Most people, if they have any idea at all, would probably say Petoskey is the state’s gem.  And it IS the state rock.  But Isle Royale Greenstone, or just Greenstone, has been Michigan’s official gem since 1973.  Found mainly on Isle Royale or the Keweenaw Peninsula, Greenstone has the fancy, scientific name of Chlorastrolite, which is a variety of the mineral Pumpellyite.  It’s often found in and around copper mines, which are abundant in the Keweenaw.  The mineral makes its home in amygdaloidal basalt.  If you’re like me, that phrase holds no meaning.  I had to look it up, so I’m happy to share its meaning.  Basically it’s a pit or cavity in the stone.  So amygdaloidal basalt is cooled and hardened lava with lots of cavities in it that have been filled in with minerals.

Once the Greenstone is removed from its host rock, it can be cut and polished.  But it’s a tricky stone to work with because it’s not really hard–only a 5-6 on the Mohs’ Scale– and it can have its own cavities and hollow spots within it.  Cutters want to expose the best “turtle-back” pattern that they can and eliminate any bad spots.  But removing a top layer of the stone is likely to reveal a different, and not necessarily better pattern. The goal is a clear pattern showing some chatoyancy.  The best stones will demonstrate that change in luster as they are tilted back and forth in the light.

Tumbled Greenstone with pink Thomsonite

Tumbled Greenstone with pink Thomsonite

Greenstone is not a particularly expensive gemstone to buy.  Even with the labor involved in finding, mining, and cutting it, there’s just not a huge market for the material.  But it isn’t an easy gem to own.  Since the year 2000, it’s been illegal to take Isle Royale Greenstone off the island. The island is, after all, a national park.  And even Keweenaw Greenstone isn’t easy to get unless you have access to the copper mine areas.  Most jewelry stores, even in Michigan, don’t carry Greenstone.  So plan on spending some time searching for your perfect piece of Michigan’s gemstone.  Whether you spend time looking along the shoreline for a rare small piece of it, or whether you search for jewelry stores that carry the gem, enjoy the journey.

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My piece of Keweenaw Greenstone! I love it!!

 

The New Birthstone- August’s Spinel

 

Natural Spinel

Natural Spinel

I have some very good news for all of you born in August.  Just recently, the American Gem Trade Association and Jewelers of America announced that SPINEL has been added to the birthstone list as an alternative to peridot.  Not everyone is a fan of peridot’s yellowish-green color, and the gem stone has a narrow range of hue.  Spinel, on the other hand, comes in almost every color of the rainbow!  The most prized color is red.  Pink and blue are two other popular hues.  So, because spinel is a relatively unknown gemstone and because changes to the birthstone list don’t happen often, it seemed important to write about it.

Peridot

Peridot

Many people have never heard of spinel.  It was recognized as a separate mineral about 200 years ago, but, until then, red spinel was often mistaken for ruby.  Some famous gems, like the Black Prince’s Ruby, which is set in England’s Imperial State Crown, are actually red spinel.  Those who have heard of it often associate it with something “cheap” or “common.”  Synthetic (aka man-made) spinel has been used for years to make the stones for high school class rings because it’s inexpensive to produce in lots of different colors that mimic birthstones like emerald, ruby, and sapphire.  Synthetic spinel is also used as the top, bottom, or both of a “triplet” that substitutes for a natural gemstone.

Natural spinel is a beautiful mineral made of magnesium, aluminum, and oxygen.  It’s colorless unless a trace element such as chromium, iron, or cobalt makes its way into the recipe.  Chromium leads to a pink or red spinel.  Iron and cobalt lead to violet and blue spinels.  A combination of trace elements produces orange or purple spinels.  These colors need no enhancement, so spinel is rarely heat-treated or irradiated.  It’s a fairly hard gemstone, scoring 8 on the Mohs Scale, and it forms in the cubic crystal system.  These qualities mean that spinel is hard enough to take a good polish and easy enough to cut and facet.  And the gem is usually eye-clean when it comes to inclusions.

Spinel is traditionally associated with Asia–especially Myanmar, Vietnam, and Sri Lanka.  More recently deposits have been found in Tanzania and Madagascar.  Large crystals are quite rare, so the value goes up exponentially, not only for great color but also for size.  While not as expensive as fine ruby or pink sapphire, natural spinel is not an inexpensive gem.  Red spinel would cost approximately 30% of the cost of a similarly sized ruby.  And pink spinel would be about 85% of the cost of a same size pink sapphire.  It’s not easy to find spinel in a jewelry store.  Maybe that will change now that it’s a birthstone, but, up until now, it’s been more of a collector’s stone.

So, take heart all of you who longed for another birthstone! It’s spinel to the rescue!!  Ask your jewelry store for a peek at its spinel.  Here’s a peek at ours.

1.28 carat pink spinel

1.28 carat pink spinel

 

 

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!

 

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 Anatomy of a Ring

Engagement Ring - Wedding Band - Michigan

The other day a customer came in to get her ring sized.  She was amazed and somewhat alarmed to learn that our bench jewelers would be cutting her ring with a saw blade in order to size it.  Her beautiful ring–a piece of art–subjected to the saw!  But jewelry is more than art and more than an expression of sentiment.  It’s also a piece of engineering.  It’s built with shanks and prongs, bails and bezels, and many other findings.  It’s adjusted or repaired with the use of tools like saws, hammers, and torches.  Using rings as our example, let’s explore the Anatomy of a piece of jewelry.

MOUNTING: This is the general name for the metal that holds the stone(s) in place and encircles your finger to keep the ring on your finger.

SHANK: This refers to just the curved part of the ring that goes around your finger.  Shanks can have profiles(or cross-sections) that can be quite flat to very round.  The width of the shank can also vary.  And the shape of the shank, while usually circular, could be oval or even rectangular.  A EURO-SHANK is curved on the sides but has a squared off bottom.  There are adjustable shanks, too, which operate with hinges, allowing more room for a ring to slide over the knuckle. 

SETTING: Sometimes a synonym for mounting, a setting probably refers more to how the stone(s) are held in place.  Setting techniques include prong or shared prong set, bead set, tension set, channel set, bar set, flush set, bezel set, pave set, and invisible set. 

PRONG: Tiny metal wires that suspend the stone, holding it in little “claws” (HEAD), so that light can enter the diamond from all sides. 

BEZEL: A frame of precious metal that surrounds the stone, bezels can be thin like a wire or wide so that the side of stone is unseen. 

FINISH: Whether the metal is shiny or more dull depends on the finish.  You can have a polished finish, which is shiny or a matte finish, which is smooth but less shiny.  Other finishes like satin, hammered, engraved or stone can give texture to the surface of the ring.

MILLGRAIN: This is a common embellishment on the shank of a ring.  It’s a border of tiny beads that acts as a boundary or edging.

I could go on–there seems to be about ten- thousand terms that bench jewelers use.  I learn a new one almost every day.  Instead, let’s re-cap with a picture and save Anatomy 102 for another day.  The important thing to glean from today is that jewelry is a designed and constructed piece of art.  It’s engineered to be art that you can wear.

Engagement Ring with an Engraved Finish

Engagement Ring with an Engraved Finish

 

 

 

 

 

 

Thanks for your Patronage

| November 25, 2015 | Reply

thanks1

We are so grateful for our wonderful customers, who come in and share their stories with us.  Jewelry always has a story, and it’s almost always about love.  When people buy jewelry, it’s often to show loved ones how much they care.  In the spirit of Thanksgiving, we wanted to share a few of our jewelry stories.

The first story is about a silver and gemstone bracelet bought in Bali in the summer of 2009.  My husband and I found it in a tiny shop in a tiny town whose name I can’t remember.  But I can remember the face of the stooped old man who owned the shop.  He couldn’t speak English, and we couldn’t speak Balinese, but, somehow, the transaction was made.  A few days later, rushing in the airport to make our flight, I looked down at my wrist and felt my heart drop.  The bracelet was gone.  It had unlatched underneath my jacket, and I never felt it slide off.  Though I searched the airport, it was nowhere to be found.  I had to leave my beautiful bracelet in Bali.

It’s a sad story, but the story isn’t over.  I called the airport security when I got back to the States.  They had found what sounded like my bracelet!  I waited, impatiently, for the package to arrive.  When it did, I opened it anxiously.  Imagine my disappointment when I opened someone else’s costume bracelet.  There seemed to be no hope.  Christmas Day, 2009, came, and my husband and kids had expectant looks on their faces as I opened my final gift.  Nestled inside the box was my bracelet!!  I started crying with joy.  “How?” I asked through my tears.  My husband has never revealed to me how he managed to lay his hands on an exact duplicate of my original Balinese bracelet.  But every time I wear it, I think of the love it took for him to find it.

The next story is really a duo of stories.  It’s a story we hear, in many unique versions, over and over again.  When a mother, father, grandparent, or even an aunt or uncle dies, their jewelry can remind loved ones of the special bond that was shared.  Every time my one colleague wears his father’s watch, it reminds him of his dad.  He received it in his father’s estate, and he wears it almost every day.  Another colleague took her father’s gold diamond wedding band, melted and re-cast the gold into a lovely cross, mounted with those same diamonds.  You would never know her cross pendant was once a ring.  But she knows.  It’s a beautiful reminder of her father.

Thanksgiving is a time to give thanks and be giving.  We hope that you have a wonderful Thanksgiving holiday, filled with family, friends, and, of course, food.

With many thanks,  All of us at Dearborn Jewelers

The Gift of Quartz

sand

Is it hard to believe that something as common as sand or dust is made of, basically, the same ingredients as the most beautiful amethyst?  Silica and oxygen are two of the most common elements on Earth, and they are the two needed to form quartz, a group of minerals which contains, among other gemstones, amethyst.  What a gift that, sometimes, the simplest and most common ingredients make an awe-inspiring product.

The “Quartz Family” is a wide-ranging group.  Amethyst is part of the large or single crystal strand of this group, along with citrine, smoky quartz, rock quartz (colorless quartz), and prasiolite (green quartz).  These are the quartz gemstones that are likely to be faceted in order to refract light.  They are more transparent, being cut from a single crystal.  There are two main reasons why these gemstones are different hues.  Trace elements such as iron can mingle with the silica and oxygen to influence the color.  Heat and/or irradiation acting on the mineral can also change its color.  Citrine, for example, is generally made by heat-treating pale amethyst.

Another branch of the quartz group is the microcrystalline strand.  Gemstones like tiger’s eye and aventurine are aggregates of many, many small quartz crystals.  These gemstones are generally translucent or opaque and are rarely faceted.  You might see them carved into cabochons or made into beads.  Colorless quartzite is an aggregate that is often dyed in various colors, sometimes to mimic other gemstones like jade.

Gemstones with cryptocrystalline structure have crystals too small to be seen without a powerful microscope.  Chalcedony, agate, and chrysoprase fall into this strand.  Chalcedony comes in various colors, both naturally and with man’s help.  Chrome chalcedony is naturally green due to a trace element of chromium.  But black onyx is actually chalcedony that has been dyed black.  Chrysoprase, one of the most valuable gemstones in the quartz group, is a translucent apple-green due to the presence of nickel.  These gemstones are sometimes faceted but usually are made into cabochons, beads or other carvings.  Agate, a multi-colored banded gemstone, can be used to carve cameos.

Quartz comes from almost every corner of the globe.  South America, North America, Australia, Africa, Asia, and even Europe all have deposits of quartz.  Because it’s so plentiful, even in large pieces, quartz is generally affordable.  We often think that the more expensive something is, the more beautiful it must be.  But that’s just not true in the case of quartz!

amethyst