Posted by & filed under Gem Knowledge, Sapphire.

Rosecut Fancy SapphiresIt’s hard to find anyone who doesn’t love sapphires, because there are so many wonderful sapphires to choose from! We thought it might be a fun time to review the different types of sapphires and perhaps add a bit of sapphire trivia to your conversational repertoire.

Blue sapphires are the most well-known and also the most popular. Most people picture rich, blueberry-blue gems when they hear or read the word sapphire. Blue sapphires are found all over the world, including Kashmir, Myanmar, Sri Lanka, Thailand, Australia, Madagascar, Tanzania and even the state of Montana! Sapphires have been used for nearly a millennium in the adornment of clergy and royalty, and of course Princess Diana received a magnificent sapphire engagement ring from Britain’s Prince Charles.

Pink sapphires have gained tremendous popularity since new deposits were found in Madagascar in the late 1990s. Until then, they were extremely rare. Even now they are fairly rare — particularly larger pink sapphires. As a result, stones half a carat or more are not cut into calibrated sizes. Instead, they are generally cut to retain as much of the rough as possible, and the result is that most pink sapphires of any size are also highly unique in terms of cut.

Yellow sapphires are often confused with fancy yellow diamonds. They show up in a very broad range of color from greenish yellow to orangey-yellow, and the most favored is saturated, vibrant, canary yellow. Because yellow sapphires tend to have fewer inclusions (seen as shaded or dark spots) than other colors of sapphire, you’ll often hear gem dealers speak of “clarity” when discussing yellow sapphires, but not when speaking of blues or pinks. And since yellow sapphires are more abundant than pink sapphires, cutters worry less about retaining the size of the gemstones. As a result, it’s very easy to find consistent, calibrated yellow sapphires.

Padparadscha Sapphires live in the color range between pink and orange. The term padparadscha itself is derived from the word for an aquatic lotus blossom, which, not surprisingly, has a salmon-y color. Interestingly, gemologists and collectors cannot agree on exactly what salmon color range defines a padparadscha sapphire. There is still some argument about how much orange, how much pink, how dark, how light . . . and we imagine this will go on for a while. But when a sapphire falls clearly in that salmon range, it leaves little room for debate and a premium is typically added to the price.  Omi has a long history working with Padparadscha sapphires, and they have graced many beautiful designs.

Star sapphires occur in nearly every color from transparent to green. The star occurs when small, needle-like inclusions of the mineral rutile are embedded in the sapphires, which create a light effect called asterism. In black star sapphires, the mineral inclusions are hematite instead of rutile.

The ideal star sapphire has a star that starts – and is centered on – the crown of the sapphire, with bright, clear rays that reach down to the base evenly and without interruption. As you might imagine, proper cutting is critical to preserve and showcase a natural star sapphire!

And now, let’s talk about rubies. Both rubies and sapphires are members of the mineral species corundum. A red corundum becomes a ruby – instead of a pink sapphire – when it displays a medium to very dark red tone. Rubies are found in many locales around the world, but the most desired source is Myanmar. You’ve probably heard of “Burmese Rubies,” and of course Burma is the name Myanmar was previously known by. Burmese rubies, known for their “pigeon’s blood” color, can be priced 30-40% higher than rubies from other sources.  Rubies are typically faceted, but star rubies (remember – star sapphires occur in every color!) are almost always cabochons.

What other colors do sapphires come in? Lime green, dark green (very rare), magenta, transparent, orange, brown, gray, black, violet, and lavender are all colors of sapphire. Many purple and violet sapphires shift color in different lights, appearing violet in fluorescent or daylight and deeply purple under incandescent light.

We could write an entire book on sapphires (and some have), but hopefully this overview helps you develop your love for sapphires, and understand a bit more about the many types of sapphires we use at Omi Privé.

Posted by & filed under Trends.

marsalapairing1Gone are the days when women waited around for a parent, fiancé or spouse to buy them jewelry. Today, according to research done by Mintel in 2015, 30% of women report buying themselves non-diamond jewelry* as a treat or even for no special reason, 19% of women report buying themselves non-diamond jewelry as a birthday gift, and 20% of women report buying themselves non-diamond jewelry as a holiday gift or for some other special event or occasion. Another 7% of women actually buy their own anniversary gifts! All that adds up to a lot of women buying jewelry for themselves these days!

Jewelry is an incredibly personal purchase. We all have different tastes, respond to different stories, and are concerned about different features. At Omi Privé, we don’t get too hung up on “selling” jewelry. Sure, all businesses need to sell, so that’s certainly something we do. But we spend far more time thinking about the design of our jewelry, the characteristics of the gemstones we select for each piece, the places those gems were found and mined, and the stories that surround these very precious gems. We know that when women go looking for something special, they know it when they see it, and they want to learn more about it. So instead of “selling,” we get to engage in conversations about natural beauty, design, and extraordinary craftsmanship. And that’s why we love our work!

* Jewelry in which diamonds are not the primary gem material, including primarily metal jewelry.

Posted by & filed under Gem Knowledge.

rough alexandrite from omi gemsPerhaps you’ve noticed how often we use the word mineral when writing about gemstones. Given the importance of minerals to our life’s work – and your jewelry viewing and wearing pleasure – we thought it might be interesting to take a moment to explore what minerals are.

First, a few Myth Busters

Most people over the age of 45 or 50 think about minerals according the designations they learned in second grade, when they were taught that all things can be assigned to the animal, vegetable, or mineral kingdoms. This is an archaic use of the term, and younger generations may have heard this information from their parents, but are no longer taught that the world can be broken down into three kingdoms.

The word mineral is also misused in geology, where anything that is obtained from the ground for use by man is called a mineral. Coal, oil, gas, granite, and obsidian are often referred to as minerals because they are mined from the ground, but for various reasons are not minerals at all.

So what is a Mineral?

The scientific definition of a mineral is something that is:

  • Naturally occurring (people did not make it).
  • Inorganic (is not made by an organism, but instead, created in the earth).
  • Solid (not liquid or gas at standard room temperature).
  • Is made of narrowly defined chemical ingredients (for example, Corundum’s chemistry is expressed as AI2O3, which means it is made of 2 aluminum atoms and 3 oxygen atoms, whereas rocks are comprised of a mixture of minerals with a much broader chemical definition).
  • Exhibits an ordered internal structure (the atoms are arranged in a systematic and repeating pattern).

There are approximately 4,000 known minerals. Many of these minerals are essential for plants to grow, are required for healthy bodies, and are used to make medicines. Minerals are also used to make the clothing we wear, the houses we live in, the cars we drive, and the roads we drive on. In fact, it is estimated that three trillion tons of mineral commodities are used to support the standard of living in the United States each year!

Are all Gemstones Minerals?

Actually, no. Amber is solidified tree resin and other fossilized organic matter, so it is not a mineral. Opal is actually a hydrated form of silica without a clearly defined shape or form, so it cannot be a mineral. Pearls are not minerals because they are formed by a living organism, and they do not have a distinctive crystal structure. Of course, anything that is created in a laboratory or made with synthetics is not a mineral, though minerals are probably part of the materials they are made of.

Thank Goodness for Minerals!

Minerals are not only essential to sustain life on this planet; the majority of gems are also minerals. Rubies, garnets, sapphires, emerald, aquamarine, citrine — all are minerals that can be cut, shaped and polished. So not only do minerals feed us, clothe us, provide beautiful landscapes and functional buildings; they are also responsible for giving us the incredibly beautiful gems we view in museums, collect in pouches and drawers, and wear as adornment in jewelry. No wonder so many of us naturally gravitate to the splendor of natural colored gemstones! They truly are the stuff of life.

Posted by & filed under Gem History, Sapphire.

Star of India SapphirePaola de Luca’s Trend Book 2017 is a treasure trove of predictions about emerging consumer needs and tastes in jewelry. One of the predictions we find most interesting is that consumers want jewelry with historical references. We’ve seen indications of this trend as well.

In the larger jewelry world, this trend may show up as an interest in coin jewelry, crown rings, and reliefs of historical monuments and art. In the colored gemstone world, history is rich with stories of royal jewels, dramatic love stories, grand thefts, and even battles.

At Omi Privé we’re not just gem nerds, we love our history too. One story that never loses its luster is the story of the Star of India, a 563-carat star sapphire that is believed to be over a billion years old. It is the size of a golf ball, nearly flawless, and it has stars on both sides of the gemstone — all of which are highly unusual.

It was originally purchased by esteemed mineralogist and collector George Frederick Kunz (1856 – 1932) on behalf of Tiffany & Co. It was part of a collection Kunz had convinced his bosses at Tiffany to build in order to gain more respect from European gem and jewelry collectors, and which was ultimately purchased by J.P. Morgan and donated to the American Museum of Natural History in New York City. Unfortunately, nothing is known about the history of the Star of India prior to its purchase in Sri Lanka in the late 1800s. Kunz himself wrote in 1913 that the Star of India “has a more or less indefinite historic record of some three centuries,” which indicates that it was mined in the 1600s; but even that may be speculation.

So the story of the Star of India begins with a mystery. Now let’s add some action. On October 29, 1964, two amateur thieves scaled a fence into the American Museum of Natural History’s courtyard, climbed a fire escape, and hung a rope from a pillar set over the 4th floor windows of the J.P. Morgan Hall of Gems and Minerals. Inside that Hall, the Star of India was on display. Hanging from the rope, one of the thieves swung to a window that was cracked open, and used his feet to open the window the rest of the way.

Using a glass cutter, some duct tape, and a squeegee, they stole 24 gems – including the Star of India. Then the thieves, Allan Dale Kuhn and Jack Roland Murphy, retraced their steps, grabbed separate taxis, and rode off with their valuable loot.

In the six months that followed, the Star of India led state and federal police on a wild goose chase involving anonymous foreign collectors, an upper West Side party palace, handsome bad boys, jilted lovers, suicide, a red Cadillac, an underwater hiding place, disguising one of the thieves as a police officer to spirit him off to Miami, and the pistol-whipping of Eva Gabor.

How’s that for a bit of history? We bet you’ll never look at a star sapphire the same way again.

Posted by & filed under Bridal, Ruby, Sapphire.

Omi Privee ring with Kashmiri sapphireThough diamonds are currently the gem of choice in engagement rings, it was only in the 20th century that diamonds became popular. Before the 20th century, colored gemstones had a long history of being considered most precious.

Engagement rings as we know them began as a result of Pope Innocent III implementing a mandatory waiting period between engagement and marriage in the year 1215. Until that time, people simply married once they made the decision to do so. Couples in the limbo between not-married and married began to exchange symbols of commitment, and the engagement ring was born. Jump forward 150-200 years, and it was the sapphire that was the favorite engagement gemstone, because it symbolized love, truth and commitment. Plus, it was believed that a sapphire’s color would fade if worn by an unfaithful or untruthful person!

Royalty were known to use diamonds in their engagement rings, but no more often than they used sapphires, rubies and emeralds. And of course, back in those centuries diamonds were extremely rare. But starting in 1870, when huge diamond deposits were discovered in South Africa, diamonds began to flood the market and prices for diamonds started to come down. De Beers launched its massive effort in to make diamonds part of every wedding in 1938.  They coined the phrase “A Diamond is Forever” in 1947 and by the 1960s, diamonds were synonymous with engagement.  That slogan was named the best advertising slogan of the 20th century.

Today we see a resurgence of interest in colored gemstones for engagement rings. Today’s brides are open to a broad range of gemstones and designs, basing their jewelry decisions on personal taste, the desire for uniqueness, and concerns about diamond origins. Colored gemstones – many of which are rarer than diamonds – offer exciting stories for today’s brides; from historic lore to the metaphysical properties of gems and the various meanings associated with colors. It appears the old adage is true: What comes around goes around. At Omi Privé, we’re just excited that colored gemstone bridal jewelry has come around again.

Posted by & filed under Craftsmanship.

One of the most important decisions a jeweler makes when creating a new piece is whether to cast or to fabricate. Both casting and fabrication have been used to make jewelry for thousands of years, so the decision about which method to use is based on several concerns including complexity of the design, intended use of the piece, and the size of the gemstone being set. But perhaps we should step back and review the two methods:

When you fabricate, you start with gold (or platinum or silver) in the form of ingots, sheet, or wire. Using hammers, torches, pliers, and other hand tools, you form it into bands for rings, backings for settings, bezels, prongs, baskets, and galleries.

Anatomy of a RingWhen you cast, the traditional method (which is still used widely today) begins by carving a model of the item you plan to make in wax. A more modern method is to design a computer model of the item using a CAD program, then create the model in plastic using a 3D growing device. Once the wax or plastic model has been created, it is encased in a plaster-like material called investment, and heated in a kiln to melt out the wax or plastic. What remains is a plaster model with an impression of the jewelry item inside where the wax or plastic used to be. Into that void you pour liquid metal, and once the metal has cooled and hardened, you break away the plaster to reveal the rough piece of jewelry.

Either method of jewelry making is a valid, artisanal process. So why do we choose to hand fabricate nearly everything we make at Omi Privé?

First, the soldered prongs of a hand-fabricated jewelry piece are stronger than the prongs of a cast piece. This is not to suggest well-cast prongs are likely to break — they aren’t.  But at Omi Privé we are setting the finest gemstones, so it is important to us that the prongs be able to stand the maximum quality test, and that means hand fabrication.

Second, many of our designs require delicate wire work. We use drawn or extruded gold or platinum wire, which is much stronger than cast metal.  Just one look at the galleries of our rings will show you the intricacies of our designs. Less skilled jewelers would choose to cast these pieces, because the hand work is extremely challenging. But true masters of jewelry making do this work by hand to achieve a more refined, more delicate, and longer-lasting piece than casting can produce.

At Omi Privé, we want to create more than beautiful jewelry. We want to create masterpieces. So our choice is almost always to fabricate, and only cast when casting is the superior choice. Because when you’re working with the most beautiful gemstones in the world, only the most masterful settings will do.

Posted by & filed under Gem Knowledge.

Mohs Scale of Hardness

Image Courtesy of GIA

If you’ve ever heard the phrase “diamonds are the hardest material on earth” (and who hasn’t?), though you may not have known it, you were referring to the Mohs scale. The Mohs scale was created by a German mineralogist named Friedrich Mohs in 1822 to measure the relative hardness of minerals. He had been hired by a banker who had a very large collection of minerals, and he wanted Mohs to curate them. In order to properly curate the collection, Mohs had to sort the minerals, and at that time there was no acceptable method for categorizing minerals. Some scientists used color, others used geographic origin, and still others used various geometric characteristics.

Mohs noticed that some minerals scratched the surface of other minerals, and using that observtion he decided to explore their relative hardness. Though the minerology establishment at the time widely criticized Mohs for considering hardness as a meaningful characteristic, Mohs was ultimately validated. Today the Mohs scale is recognized as one of the most important measures of mineral categorization.

We’ve already mentioned that the diamond is at the top of the Mohs scale. Its measure of “absolute hardness” is 10. So what is at the bottom? Talc, with a measure of 1. We all know talcum powder, but some of the other elements in the Mohs scale — like fluorite and calcite — are less familiar to us in their mineral form. However, you probably do know minerals like quartz (7), and topaz (8).

Another good way to wrap your mind around Mohs hardness is to consider the Mohs rating of more every-day items:

  • Maple or Oak hardwood floors are 1.3 – 1.4
  • A fingernail has a hardness of 2
  • The average knife blade has a hardness of 5
  • The window panes in your house are 5.5
  • Granite countertops are typically around a 7
  • Tempered glass — like the average windshield — is usually a 7
  • Bulletproof glass could be anywhere from 8 – 9

The Mohs scale is very important to us as we decide how to set various gemstones. Some gemstones are much softer than others, so how a gemstone will be worn must be considered. You’ve probably heard before that pearl rings are best saved for special occasions. Why? Because pearls are between 2.5 – 4.5 on the Mohs scale, so they scratch rather easily. Along with pearls, amber (2-2.5), coral (3-4) and malachite (3.5 – 4) all tend to last longest when worn in pendants or earrings because of their relative softness.  Take more care in storing these softer gemstones by wrapping them in cloth or placing them in separate pouches.

At Omi Privé, we admire any gemstone that represents the best of its kind. If we find something rare and beautiful, we want you to see it. But for the most part, we work with gems that are a hardness of 7 or above, because these gems allow the most options for wearability. Diamonds may be the hardest on the scale at a 10, but rubies and sapphires are very durable at 9. Topaz, chrysoberyl, and spinel have a Mohs hardness of 8, and aquamarine and emerald are between 7.5 – 8.  Quartz is a 7 and is the most common mineral on Earth.  Because quartz is the most common mineral in dust, any gemstone softer than 7 can be scratched by common dust and, therefore, should be treated with more care than harder gems.

So the next time you’re looking at a gemstone, remember that it’s not just characterized by its color, its type, or its absolute beauty. Every gemstone also has a hardness rating on the Mohs scale, thanks to a fellow nearly 200 years ago who was faced with a sorting project.

rough alexandrite from omi gems

Posted by & filed under Alexandrite.

I am really appreciative of the fact that we humans see in color. It’s easy to take for granted, because it’s like breathing. We open our eyes, we see color. Do you remember how The Wizard of Oz starts out, in black-and-white? No matter how many times I watch that movie, I still gasp when Dorothy lands in Oz and suddenly the world is almost blinding with color. When it comes to color, we really do live in Oz.

I think that’s why so many people love colored gemstones. Many of the every-day colors we encounter are muted, and we get so busy we don’t even notice them. But then you see a rich red ruby or an eye-popping pink sapphire, and the energy flows into your eyes and straight to your brain. Gemstones are color personified. Read more »

Omi Privee ring with Kashmiri sapphire

Posted by & filed under Fancy Sapphire, Kashmiri Sapphire, Sapphire.

Most people understand that gemstones are from the earth, and that they have been there for a long time. But a long time is such an abstract concept. However, when Gübelin Gem Lab is able to give the age of a gemstone using radiometric dating, that abstract concept becomes very real. How long is a long time? Think in terms of millions of years, not hundreds of thousands.  Here is an excerpt from the May 12, 2016 issue of the Gübelin Newsletter #46, on determining the absolute age of Kashmiri sapphires.


Kashmiri sapphires determined to be 25 million years old

Last fall, for the first time ever, the absolute age of a high-value gemstone has been determined. Our geochemical specialist Klemens Link used radiometric dating on the in-house Laser Ablation ICPMS facility. The method and results are published in the latest issue of the Journal of Gemmology, Vol 34, Issue 8. Meanwhile, age determination is applied regularly in our lab on rubies and sapphires, supporting the distinction of African and Sri Lankan sapphires from the Burmese and Kashmiri ones.

The determination of the exact age of Kashmiri sapphires, however, was not yet undertaken, until the Gübelin Gem Lab initiated a research project jointly with Prof. C. Liu, and Dr. C. Zhang of the Institute of Geology and Geophysics, Chinese Academy of Sciences in Beijing. Zircon crystals included in samples from the Gübelin Reference Collection have now been analysed by LA-ICPMS in the Gubelin lab, and by high-resolution SIMS at the IGGCAS in Beijing. The respective uranium-lead ages are 26.8 (±3.8) million years, and 24.97 (±0.22)  million years, mutually confirming the results.

 

Omi Prive Kashmiri sapphireThis is exciting news for all of us at Omi Gems and Omi Privé. Our Kashmiri Sapphires are among our favorite gemstones. To be able to imagine them in terms of their real age makes them even more magnificent in our eyes.

The platinum Omi Privé ring shown on the left and at the top of this post features a 3.43 carat Kashmir Sapphire accented with French-cut tapered diamond baguettes and round brilliant-cut diamonds.

alexandrite with spinel

Posted by & filed under Alexandrite, Spinel.

About a year ago, interesting colors of purple spinel started showing up in the market. Spinel comes in a beautiful range of reds, pinks, blues and purples, but until now I haven’t seen much of the intense purple you see in the photograph at the top. This deep, rich purple is very similar to the color of alexandrite when viewed in incandescent light. Read more »