Tag Archives: birthstones

When I was younger I was always annoyed that everything October was pink. October’s birthstones are opal and tourmaline. Opal being a pricey stone and not super cheap even in lab grown options, pink rhinestones were the way to go in key chains, toy rings, and other such birthday/astrologically themed trinkets.

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Blue Beyond the Sea

1539-cu-lapis

A piece of lapis with a wire work bail I made to echo its pyrite sparkles.

 

Lapis is sometimes considered a secondary birthstone to sapphire. That’s probably due to its brilliant blue color, and the fact that through the middle ages the word sapphire was used pretty loosely!

 

 

Lapis is a vibrant blue stone consisting of lazurite and usually pyrite and sodalite as well as a host of other minerals. It’s the pyrite that gives lapis its midnight sparkle of stars.

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The Autumn side of August

The green gemstone peridot is the most popular birthstone for August, but it has another, less gemmy birthstone, sardonyx. It seems fitting that one of August’s stones is all sparkle and leaf green, while the other is duller and browner and edging into fall.

 sardonyx

Sardonyx is a type of onyx that can be found in shades of browns and reds as mixed with black or white. It’s more common than black onyx (which is naturally bands of black and white-not solid), but since black onyx is a higher demand stone, sardonyx is often dyed black. The sard prefix probably comes from a Persian root for yellowish red. Its colors form very even and straight bands.

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Royal Purple

Amethyst from Erte’s Precious Gems Suite

Amethyst is the traditional birthstone for the month of February.

 

(I remember being jealous as a kid, since there were purple stones for February but October always got something pink instead of opal or even fake opal!)

 

Iron impurities in quartz give amethyst its wonderful purples-from pale lilac to royal.

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Regal Greens

4th century gold Tunisian necklace in emerald, sapphire and pearl.

Emerald is May’s traditional birthstone, but since good quality emerald is getting harder to find (I still say the most beautiful ones I ever saw were at the British museum in ancient jewelry) it seemed a good month to look at two other gorgeous green gems.

 

Especially since outside the spring greens are starting to ripen!

 

Chrome diopside

Chrome diopside really needs a trade name. Despite the fact that it sounds like a polishing agent, it is a beautiful green stone that is sometimes used as an emerald replacement.

 

The word diopside comes from Greek, meaning double shape, after the shape of its crystals. Chromium is the element that gives chrome diopside its name and color. Traces of chromium are also what make emeralds green. Oddly enough, it’s also what makes rubies red!

 

Chrome diopside rough

Chrome diopside can indicate proximity to diamond mines. So some people search for minute crystals as a hint of where to mine. Most chrome diopside come from Siberia, near the diamond mines there. It is also sometimes found near the diamond mines of South Africa.

 

It is a much softer stone than emerald. The hardness of stones is measured on the Mohs scale, and chrome diopside sits around 5.5-6.5. That means it is more easily scratched than emerald. It is best used in earrings and pendants; or in rings with a protective setting.

 

Emerald with jardain

Emeralds are tougher. They are rated at 7.5-8 in the Mohs scale; but it is one of the few gemstones expected to have inclusions. Inclusions break up the crystal structure and make both visible and structural flaws.

 

(One of the things I love about emeralds is that even the best gems are expected to have flaws. Visible flaws in emeralds are called jardain, French for garden, for the foliage effect flaws add to the stone.)

 

Green tourmaline showing some of the color variations to wonderful effect. Faceted by Robert Schock.

Tourmaline sits between these two on the Mohs scale at 7-7.5. The name tourmaline covers a large group of related stone species that come in all different colors: clear, yellow, pink, red, brown, green, violet and black. Multicolored crystals are more common than single colored ones.

 

Tourmaline crystal

Originally a lot of the different stones each had their own name; For instance verdelite was the name given to all shades of green and indicolite for all shades of blue tourmaline. Now they’re mostly just referred to as green tourmaline or blue, etc.

 

One of the classic color combinations for tourmaline is the watermelon tourmaline: a crystal that’s green on the outside and shades to pink on the inside, so that the cross-section looks like a slice of melon. (I don’t actually like watermelon, but I’ll take a slice of watermelon tourmaline any time, thank you.)

 

The floral carving is an interesting twist on the watermelon slice tourmaline.

The intense pink and green are normally the most desired tourmaline variants. The pinks range into the most delicious raspberry colors while the best greens can almost put emeralds to shame.

 

Tourmaline is found in many places all over the world. Brazil is the largest supplier, but mines are found on every continent except Antarctica. In the United States tourmaline is found in Maine and California, and is the former’s state stone.

 

I mixed chrome diopside and green tourmaline for an emerald effect in this summer green tree of life pendant.

I mixed chrome diopside and green tourmaline for an emerald effect in this summer green tree of life pendant.

* Care and feeding of chrome diopside- it’s light stable, so it won’t fade in sunlight like some other gems (yes, even natural ones) however, it is sensitive to heat and hydrofluoric acid, so pieces with chrome diopside shouldn’t be cleaned using a steam or ultrasonic cleaner

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Don’t eat the Pomegranate

Garnet is January’s traditional birthstone. I don’t get to work with it as often as I’d like. As a gemstone it’s hard to find large enough to tie into wirework, but I like to use it in beaded accents. I especially love to combine it with pale gems like moonstone and rutilated quartz. Garnet can bring a piece a very modern dramatic feel, or give it a sense of depth and history.

Snow White and Rose Red in silver, bone, enamel and garnet by Eleonore Pieper

 

After all, it’s a gemstone with a long history.

 

4th century Hunnish fibula (pin) in gold and garnet

 

By the bronze age people were using it both in jewelry and as an abrasive. It’s been found in ancient Egyptian, Greek and Roman jewelry. In ancient times garnets were carried by explorers as talismans against the dangers of the dark.

 

 

The name garnet comes from the Latin word for grain, probably because the red crystals reminded people of pomegranate seeds.

 

Striking garnet pomegranate by Natalia Moroz of WingedLion

 

In Anglo-Saxon times square garnets set in gold for a cloisonné effect were inspired by garnet and enamel pieces all the way from Byzantium!

 

Anglo-Saxon hilt fitting

Garnet is the name for a group of different types of stones with similar chemical forms but different chemical compositions.

 

Different chemicals=different colors, not all garnets are red! These are called different species of garnet.

 

Some of the garnet spectrum…

 

Since they have different chemical compositions they also have different hardnesses. Most are hard enough for everyday wear, even on rings.

 

The three species you’re most likely to come across are:

 

-Almandine-one of the hardest. The good quality dark wine red is used for gems and the lesser as grit for drills and sandpaper. This is probably the one that pops to mind when someone says garnet.

 

Burning coal, wire wrap of a garnet crystal in schist.

Burning coal, wire wrap of a garnet crystal in schist.

 

For those of you who like reading historical novels, almandine is what was once called carbuncle. That word has roots in the Latin for live coal-you can see crystals of garnet embedded in metamorphic rocks.

 

-Pyrope-(from the Greek for fire-eyed-is it bad that I think that would be a great name?) is mostly red in color, crimson with a hint of orange.

 

My favorite version of this species is called rhodolite garnet. (Found in North Carolina and East Africa, go figure.) It’s a chemical mix between pyrope and almandine and somehow looks like neither. It has a wonderful purplish pink cast. Rhodolite is almost always cut into gemstones and rarely made into beads or chips.

 

Rhodolite garnet

 

-Grossularite-garnets are often really pretty, despite the terrible sounding name! (Apparently it derives from a name for gooseberry, what the crystal clusters are supposed to resemble!)

 

One variation of this is tsavorite garnet, which is an amazingly beautiful green created by traces of chromium. It’s only been known since the seventies and is still working its way into the market, but it’s gotten much more popular in the last decade or so. (Perhaps as good quality emeralds are getting harder to come by?)  If green were a primary color, it’d be tsavorite. Sadly the crystals are normally found shattered, so large stones are rare.

 

Tsavorite garnet

 

Garnets practically run the spectrum. They’re a little short on blue, but there are rare blue-green ones that change to purple under incandescent light!

 

(*Note on the care and feeding of garnets: soap and water are your best options. Most almandine and pyrope and pretty stable, but some species can be hurt by sonic or steam cleaning.)

A chart with further species and varieties of garnet

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September Shades

I realized that I haven’t geeked out over the gemology of birthstones in a while. So a slightly late visit to September’s traditional birthstone, sapphire.

Sapphires are a gemstone variant of corundum. Red gemstone corundums are known as rubies, every other color is categorized as sapphire. (Despite the very name coming from a Greek word for blue.)

For a long time the word sapphire was applied to different stones. Even into the Middle Ages a reference to sapphire was probably to what we now call lapis lazuli.

Corundums are composed of an aluminum oxide, the bond between the aluminum and the oxygen atoms are short and the atoms are nestled tightly together. This makes them comparatively dense despite being made of light elements, and it makes them durable. As mentioned with rubies, corundum is second only to diamond for hardness. The majority of corundum found is used for industrial purposes.

Because of its sturdiness corundum lasts long after other sediments wear away. Since it is dense, it tends to be found in placer deposits (where erosion and gravity have essentially sifted the heavier bits and pieces together into a gravel over the millennia) and alluvial deposits (where water washed away the original sediment).

For traditional blue sapphires, value is determined by the color of the stones-how pure, how vivid, and how dark. Generally color wise the bluer the better. The blue color comes from traces of titanium and iron.

Monatana’s Yogo sapphires come in a wide range of colors.

 

A small amount of purple secondary hue is considered acceptable, and if subtle enough, can even raise the value of the gem. Vanadium is the coloring element that brings purple and violet (and orange!). Any trace of green (a smaller iron content) lowers it vastly. (I don’t know why, sounds like it’d be a lovely color to me!) Likewise, the richer and more saturated the color the better.

Depending on who you ask the most preferred shades are either an almost primary blue or a slightly lighter rare cornflower blue found in a small part of the Himalayas.

Recently a pink-orange sapphire variant known as padparadschah (chromium and vanadium) sapphire has gotten very popular.

Traditionally sapphire has symbolized loyalty, faithfulness, sincerity and truth. The richness of its color keeps it associated with nobility and royalty. And despite its myriad of shades, it is first and foremost the blue to which every other gem is compared.

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