Tag Archives: birthstones

A Gemstone of the First Water (And no, not diamonds)

 

An enormous aquamarine crystal and Dom Pedro – the gemstone cut from it.

Aquamarine is the traditional birthstone for the month of March.

 

Aquamarine means seawater. It’s the perfect name, since the stone ranges from pale green to middle blues. The shade depends on the how much of different forms of iron impurities the stone has. (A different iron produces yellow and a combination makes a dark blue!)

 

Compared to emerald, it’s a relatively common form of beryl-it’s found all over the world, but most gem quality stones come from Brazil.

 

Pale aquamarines can be confused with many other types of gems.

 

In the 1740s a huge diamond was mined in Brazil. It became the property of the Portuguese royal family-the Braganzas. This Braganza Diamond vanished. Some believe it was cut into much smaller gems and set in the crown jewels. In this case the famous diamond might have been a particularly brilliant aquamarine or white topaz. (Apparently the reports can’t even agree on what color the diamond was-famous, but poorly reported!)

 

There’s a beautiful carved aquamarine, also of Brazilian origin, just recently acquired by the Smithsonian Museum of Natural History. It’s known as the Dom Pedro and is 14″ long and almost 5 lbs.

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Topaz seems to be winning…

Erte’s Topaz, a part of his Precious Stones Suite, is a November gem of a different sort. It’s inspired by one of November’s traditional birthstones. (The other two being citrine and tigerseye. Since topaz also inspired a piece by Mucha, I think topaz is hogging the limelight…)

 

I’ve known of Erte for a long time, and in many ways he’s my touchstone image for Art Deco, but outside of knowing his style I never thought much too much about him.

 

So I hadn’t stopped to think about that iconic name, as streamlined and deco as his art. Not a surprise that it’s a pseudonym. I always link Erte to Paris, so it was a little more of a surprise is that he was born in Russia. His birth name was Romain de Tirtoff. He used the French pronunciation of his initials to distance himself from his career military family.

 

Erte was famous for his Art Deco fashion and set designs. Born in 1892 he was lucky enough to not only enjoy being part of the emergence of deco in the 1920s, but lived help its revival in the 1960s and his enduring influence on art and the fashion industry.

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O is for October and Opal

Precious opal is October’s traditional birthstone.

 

It’s one of my favorite stones, at least to admire if not to work with. Opal is similar to the feldspars in that it has the addictive quality of each gem being different. Boulder opals, trails and pools of opal still in their matrix stone, have a wonderful narrative feel. Like gazing at clouds they have shapes and stories and weather in them.

 

Opal under a microscope.

Their chemical composition is hydrous silicon dioxide. The stunning colors come from the fact that opal is composed of tiny spheres layered in essentially a silica jelly. The light passing through and refracting off of them is what gives them that fire. How even the spheres and how close together changes the intensity and color.

 

Opals are between 3% and 30% water. The color can diminish if the opal loses some of its water through heat or cracking. Keeping them in or near slightly moistened cotton wool can prevent drying out over time. Sometimes the play of light in old opals can be partially resuscitated with oil or epoxy resin.

 

Couldn’t get a decent photo of the ring I’m trying to salvage, so a boulder opal I wrapped with amethyst instead 🙂

(I’m trying to use oil treatments to save the opal from an old beaten up poison ring. But it was a poison ring, with my birthstone, I had to try it!)

 

Some attribute the stories about opal being a cursed gem to the fact that special care needs to be taken when working with it. It’s a soft stone, so sensitive to knocks as well as to heat, acids and alkalis.

 

(I can sympathize with this, I got some Ethiopian opal wet and that was the end of that…I’ve never had trouble with any other sort, but then wire wrapping doesn’t tempt fate too much in terms of either heat or pressure.)

 

The same is true of wearing them. They’re stunning and not particularly high maintenance, but rings especially are susceptible to being knocked about and dried with or abraded by harsh soaps. So part of the bad luck bad rap may be also be that heirloom quality rings don’t seem to last as long as other gems unless they’re well taken care of over the years!

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A Sparkle from a Moonstone

Sheer blue moonstone.

I love so many different types of stones that choosing a single favorite would be like choosing a favorite dessert-totally impossible. Sometimes you want chocolate, others ice cream, or perhaps it’s fresh fruit you’re craving…

Moonstone is one of my favorites.

It’s a type of feldspar, like labradorite (another favorite of mine). Feldspars are a family of silicates that make up about 60% of the earth’s crust. Large parts of the moon’s crust are composed of feldspars too.

Moonstone is one of the traditional birthstones for June, along with alexandrite and pearl.

Moonstone has a beautiful shimmer-called adularia-the traditional color is blue, and the nearly clear moonstone with that ghostly rich blue is especially highly valued. There is also grey moonstone and peach-both have a soft white shimmer, and rainbow, which normally is a white or white/clear base with many different colors. The colors come about because the stone’s structure is layered, and those layers refract light at different angles. (Like a built-in faceting system!)

A rainbow moonstone piece with peridot.

Moonstone sterling and gold fill pendant

A newer moonstone pendant. They’re tough gems to photograph. The shimmer of this is more on the purple side of blue in most lights. You can also see the spiral from the back through the translucence of the stone.

I like working with rainbow moonstone because of the gorgeous range of colors. The whole rainbow really will appear in some pieces. I also like the fact that each stone will have its own unique pattern of shimmer and color play.

It is a comparatively soft stone. It has a Mohs hardness of 6, which makes it softer than quartz or garnet (though harder than opal) and more easily scratched. I try to avoid the temptation of moonstone rings, since those take the most knocks.

(Title from Cat Steven’s Moonstone.)

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A Study in Emerald

A quick conflation- emerald is May’s birthstone, and today is was the last episode of BBC’s Sherlock on PBS. Who knows how long until the next one. So I’m letting some fangirl out. (And going to go read The Adventure of the Empty House for meagre consolation.)

Neil Gaiman’s brilliant A Study in Emerald is a fun mix of Doyle‘s world and Lovecraft‘s mythos is available on his website. As a bonus this version looks like an old fashioned newspaper. Very fun!

A quirky collection of emerald Cthulhu and Sherlock themed crafts in honor of May’s birthstone and Gaiman’s story. (Yes, the comma was left out intentionally, they’re all emerald colored pieces!)

 

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Gems underfoot

I loved Ann Hinde’s display for the International Flower Arranging show’s mineral theme when I saw it this summer. It was inspired by an amethyst geode.

Amethyst is a popular stone, one of very few naturally occurring fully purple gems. It is the traditional birthstone for February. Amethyst is a variant of quartz. Iron impurities give it those beautiful shades of purple. Regarding its famous color-if you run across prasiolite, sometimes called green amethyst, just be aware that it’s most likely heat treated or irradiated. (It’s not an issue, so long as you know and aren’t being told or charged for the natural gem. They are a lovely mint green, it’s just that the natural stone is extremely rare.)

geode with amethyst pendant

Geodes are partially filled hollow cavities in rock that are lined by minerals. Their name comes from the Greek for earthlike. (As in Gaia.)

One example of a geode would be a gas bubble in lava. That hollow stays and over time solutions containing dissolved minerals can filter in and leave deposits within the hollow, often resulting in layers of agate and then layers of quartz and/or calcite crystals.

Studying the order of the layers can give a window into the geologic history of the area in which the geode is found.

I like working with slices of geodes because you get to see that external skin and the swirls of agate layers as well as the sparkling crystals.

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April Sparkles

APRIL is the cruellest month, breeding  
Lilacs out of the dead land, mixing  
Memory and desire, stirring  
Dull roots with spring rain.

It’s also the most expensive in terms of birthstone. It’s traditional birthstone is diamond, that incredibly expensive cousin of graphite. It is a beautiful stone with an interesting (and brutal and sordid enough for an opera- soap or Wagnerian take your pick) history. It is in some ways a newer gem, not really making any impact until more advanced gem cutting came along. It’s an unimpressive stone until cut properly, so lacks the raw appeal and richness of the semiprecious stones that can be polished into cabs or precious stones like emeralds and rubies that can shine even in rough cuts. For information about diamond history and mining I’d suggest Tom Zoeller’s book The Heartless Stone. It was an excellent read and covered a lot of ground at a pretty good pace.

Moonlitcreek's clever take on April's birthstone.

There are plenty of beautiful pale gems. White sapphire, topaz…the less impressive but omnipresent cubic zirconia… My favorite alternative is an option I stumbled across on deviantart. Another wrapper had the clever idea of making a herkimer diamond birthstone wrap for a friend. It’s never something I’ve had to ponder, I’ve no April birthdays to gift for, but I thought it was a really cute option. I like Herkimer diamonds anyway. Much more pocketbook friendly.

Herkimer diamonds are called such because they were first found in Herkimer County in New York, and their popularity with collectors earned the diamond part. They were apparently first found by workers cutting into the stone of the Mohawk River Valley in the 18th century, then later mined by geologists.  They’re double pointed six-sided quartz crystals that occur in tiny darker crystal lined cavities in the paler rock. Sometimes they’re found in larger pockets. Many of the crystals of some sort of imperfection, but an impressive number are clear and sparkle nicely. The amazing part is that the lovely shape is natural. Clear quartz alone isn’t wildly exciting.

The impurities range from the common and disapointing-like cloudyness or malformation, to the amazing-crowns of crystals growing together, ones impaled on rock like scepters. I think the most interesting imperfections are the fluid inclusions, little pockets of water trapped inside these amazing crystals. It’s just fascinating, what other minerals are in that water, what was the earth like when the water was trapped?

I did a very brief tourist stint at trying to mine them. It was a bit theraputic in a way at first, swinging a sledgehammer to beat the hell out of the rocks. Basically you’re looking for traces of those cavities (also called vugs) in the rocks, and then hoping to find herkimer diamonds in them. It gets very hot very quickly, so we didn’t last too long in a summer afternoon. I had a very patient tween try to explain to my friend and me the best ways of looking for them. (From his patience I suspect he was used to dealing with younger siblings…) The afternoon ended in a few tiny crytals, a smashed thumb for me, and popsicles for both of us. I’d love to try it again at a better time of day, with proper gloves and a bigger sledgehammer.

Later I cheated and bought a crystal still partially in its vug from a dealer at an antique show. (Cold drinks, coffee, minerals *and* jewelry, that’s a tough combination to beat.)

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