Anna Sheffield

Diamond School

Welcome to Diamond School, the Anna Sheffield guide to what are quite possibly the most appealing and mysterious of the earth’s ancient, alchemical materials—diamonds and gemstones.

From the fundamentals of the 4Cs and the search for flawless beauty, to the delightful balance of perfectly-imperfect diamonds, we hope this guide to precious gems and fine jewelry will help to inform and empower you as you seek out stones that are uniquely meaningful to you—and perfect for your love.

A white background with sprinkled different colored stones off to the right side of the image.

Diamond School

Cut & Shape

The Cut and Shape of a diamond are distinct yet interrelated. When using
the term Shape, we are essentially referencing the silhouette, or outline,
as seen from the top of the diamond. While Cut refers to the overall arrangement of the stone's facets and the way light is reflected through them. Put simply, Shape is an aesthetic choice, and Cut contributes most to how beautifully a gemstone sparkles.

Explore Our Cuts & Shapes

Round
Rose
Oval
Pear
Marquise
Trillion
Emerald >
Radiant
Baguette
Cushion

Pure symmetry and perfect simplicity—round is the most popular diamond shape. Within this cut, the allure of time: choose between Modern Round Brilliant (MRB), a cut created after 1945 which features 58 uniform facets, perfected with technology to optimize the prismatic qualities of the diamond. Or if you prefer pre-war provenance or a more subtle shimmer, there is the Old European Cut (OEC)—antique hand-cut diamonds whose sparkle subtly reflects the individual artistry of the cutter in each facet.

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Named after the flower, rose cut diamonds offer a luminously subtle sparkle, as they refract less light than full cut diamonds—their broad facets reflecting light mostly from the stone’s surface. With a dome-shaped top and a flat bottom, rose cuts look like a lot of diamonds from above, and come in a variety of shapes. Their antique allure pairs beautifully with diamond pavé or the non-traditional look of a natural black diamond.

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An elongated form of the Modern Round Brilliant, oval cut diamonds are a classic, graceful shape, and when it comes to cut, they are all about proportion. Like the pear and marquise, ovals optimize carat across the table and crown of the stone, and can appear larger than round diamonds of a similar weight.

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Created in 1458, the pear cut, AKA the teardrop, was the first faceted stone embracing asymmetry, through pairing the faceting of a round and marquise. An ideal pear cut has 58 facets for optimal brilliance and fire, but not all pears are cut to sparkle from within. Our black, champagne and hazy grey diamonds are often rose cut, with the facets on top eliciting shimmer from the stone’s surface.

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A diamond shape first commissioned by King Louis XV of France, the marquise cut was created to resemble the smile of his favorite mistress, the Marquise de Pompadour. A modified brilliant cut, the classic proportions of the stone are 2:1 though they can be beautiful in more elongated versions as well. This is another shape whose crown surface makes it appear larger than other stones of the same carat weight.

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The trillion cut is a triangle shaped stone comprised of three equal sides. Most often seen as accent stones on the Bea ring or Atelier Series designs, our trillions are frequently inverted-set, with their pyramidal side facing up, for a beautiful yet unconventional look.

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The concentric, linear facets of an emerald cut, created by the parallel step-cuts in the stone, make them a timeless and sophisticated choice. Most iconic in our Bea ring design, this shape is ideal for flawless white or champagne diamonds, since color and clarity are magnified in the large, open facets. Black diamond and blue sapphire, which highlight the symmetry of the cut, are two dark stones used most often in the collection.

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Invented and patented by the Radiant Diamond Cut Company as recently as 1977, the radiant cut features 70 perfect machine-cut facets within a square to rectangular shape. With fleet sides and an unrivalled brilliance, the radiant is a marriage of the round’s sparkle and the emerald or princess cut’s linear outline.

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Much like an emerald cut, the baguette is a step-cut diamond that dates back to the 1920s. Most often seen as accent stones in our Theda ring, the slender, geometric lines of the Baguette add a distinctly Art Deco feel to the silhouettes and center stones they accompany.

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A square-ish shape with softly rounded corners, this cut originated in the 1900s as the ‘Old Mine Cut’, so named for the stone cutting which took place at the crystal’s origin. The proportion and number of the facets has been perfected over time, and the cushion cut is still loved for its antique look and vibrant sparkle. Cushion is a beautiful, timeless silhouette for anything from a pitch black diamond to a fancy yellow or flawless white.

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At Anna Sheffield, we work with a select set of shapes and cuts ideal for our designs; each stone is chosen for its particular combination of attributes from brilliance to timelessness, perfection to uniqueness.

Diamond School

Clarity

Formed over eons deep within the earth, the creation of a diamond is part science, part alchemy.
Their transformation from carbon atoms to precious gemstone leaves a unique imprint: arrangements of tiny imperfections—called inclusions—that can be more, or less, visible.

An image of a white diamond, a grey diamond, and a black diamond on a flat surface

Graded on an 11-point scale created by the GIA, the size and position of
these blemishes is evaluated to determine the Clarity Rating. On one end, we work with stones that are flawless (FL) to very slightly included (VS1, VS2) though not visible to the naked eye. On the other end we celebrate and create jewelry with highly included stones—but only those whose one-of-a-kind arrangements within the diamond balance the perfectly imperfect, creating notable, singular beauty.

FL

FLAWLESS
IF

INTERNALLY FLAWLESS
VVS1, VVS2

VERY VERY SLIGHTLY INCLUDED
VS1, VS2

VERY SLIGHTLY INCLUDED
SI1

SI2, SI3

SLIGHTLY INCLUDED
I1, I2

I3

INCLUDED

Grade

Non-Included

The number and location of inclusions determine a stone’s clarity rating. Some diamonds have no inclusions and are graded as flawless. The less inclusions a diamond carries, the more rare, and therefore more expensive, it is. However, only when a stone scores at or below the Slightly Included (SI) range do you begin to see imperfections with your unaided eye. A tip: diamonds with a clarity of VS2 or VS1 offer great value, as inclusions won’t be seen, but the price per carat is far below that of a Flawless stone.

Included

We source a number of one-of-a-kind included diamonds, and each is individually selected by Anna for it’s unique beauty, a story of the elements writ within the stone. A diamond’s inclusions each resemble their namesake ‘imperfection’ such as: cloud, feather, crystal, cavity, knot, and bruise. Their attraction lies in the aesthetic arrangement of these elements within the stone, each like a tiny work of art, or more accurately, nature.

Diamond School

Color

The result of trace amounts of nitrogen and other elements present when their crystals form, diamonds' natural hues can range from perfectly colorless, or white, to grey, black, yellow, blue green and even pink. At Anna Sheffield, we love the flash of a flawless white as much as we adore the subtle intonations of grey and champagne and the richness of black diamonds.

D - F
Colorless
G - J
Near Colorless
K - M
Faint
N - R
Very Light
S - Z
Yellow

The diverse range of gemstones allows for a wide variety of exceptional jewelry pieces at different price points and holds true that beauty is in the eye of the beholder.

When it comes to the spectrum of white diamonds, the grading system created by the GIA lays out color on a scale of D-Z, with the rarest and most colorless in the D-F range, and the darkest earning a Z. Our selection of white diamonds sits on the scale from G (near colorless, and lovely when set in colored gold) to a perfect D. It’s worth a note that with stones graded from L,M,N and onwards, oftentimes spectacular color emerges!

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Yellow diamonds have their own color range, measuring the hue in saturation from ‘Fancy Light’ to ‘Fancy Dark’ with ‘Vivid’ being the most rare of the vibrant yellow diamonds. And while yellow diamonds do become more expensive once labeled a fancy vivid color (you may have heard of the famous Canary diamond!), each hue has its own distinct beauty. We love the intense sparkle of yellow radiant cut diamonds, set in our Bea three stone ring, as much as we delight in pale yellow set in a Hazeline solitaire.

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Champagne diamonds, though romantically named for the bubbly elixir, are in reality color graded on a spectrum of brown. The C scale, similar to the D-Z of white and off-white, goes from C1 to C8, where C1 is the lightest, most faint color and C8 is the deepest, most saturated. The beautiful part of the champagne category is that the hues vary, from what we affectionately call vanilla creme soda to darker shades more like root beer. Some stones even have a peachy cast, resembling the subtle sparkle of pink champagne. Each is unique in this combination of hues; we love the look of these diamonds set with tonal rose gold.

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When it comes to grey diamonds, the range is so beautiful and varied that only nature could have created them. On one end of the spectrum is the rare (and expensive) Fancy Grey diamond, displaying a perfect harmony of color with high clarity. On the other are the highly included and utterly unique stones we often refer to as hazy or smoky—also known as salt-and-pepper diamonds—exhibiting soft cloud-like inclusions. A faceted diamond with a lustrous opacity—smooth and evenly distributed within the stone—along with a beautiful surface polish is what we look for in the hazy grey diamonds we use.

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Even something as simple as black in the world of diamonds becomes wonderfully diverse. We work with two types of black diamond: natural (included and irregular in appearance) and heat-treated (uniform in pitch), each captivating in their own, unusual way. The placement and density of feathers, wisps and speckles in natural black diamonds can give their appearance a painterly quality, like ink swirled in water, or an infinite depth, which we named “galaxy diamonds.” Whether opaque or varied, each is a tiny masterpiece of the earth.

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Diamond School

Carats

Diamonds and precious gemstones are sized by their weight in metric carats, with one carat equal to 0.2 grams and each carat measured precisely to the 100th decimal place. As precious material, diamond prices generally increase with carat weight, but one must also take into consideration the other 4 Cs—color, clarity, cut, and character. Certain diamonds by virtue of their crystalline structure or the faceting of their cut, create variances in carat weight.

Black diamonds are naturally denser, and they are often cut to maximize the weight of the material from which the stone is rendered, which doesn’t impact quality since they need not reflect light from within. These stones are deeper and heavier in proportion, so a 1ct black diamond will look smaller than its counterpart in white or off-white.

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Rose is a beautiful antique style cut, faceted only on the domed, upper surface of the stone, and instead of a pavilion, the inverse is flat. The brilliance is more subtle, but they appear much larger from above, with less carat weight (and therefore less cost) than other cuts of a similar diameter.

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As with rose cuts, what you see from above can look like a lot more diamond than what the carat weight suggests. This is due to the shallow parts of the cut, revealed in the underside or pavilion of the stone.

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a black diamond round held by tweezers with a white background

a loose white diamond marquise held by tweezers on a white background

Diamond School

Character

There are attributes to all gemstones–diamond and otherwise–that just can’t be summed up in a neat formula for color, cut, carat or clarity. Enter the 5th C. Quite possibly the least discussed yet truly impactful C is the one we refer to as Character. Character doesn’t come with a grading system, but it can speak to those almost indefinable traits that a molecular oddity created in the center of the earth (or in space!) might just have. That special twinkle that one stone might have that another does not. Those grey and black wisps and whirls that align inside the crystal just so. A hue that doesn’t quite fit in the scale of champagne. The feeling that this particular stone is calling to you! These are the ‘perfectly-imperfect’ attributes of Character that set diamonds apart.

A white diamond cushion, grey diamond marquise, and champagne diamond round sit on a flat surface side by side

Diamond School

Precious Gemstones

Neither too dark nor too pale and an even distribution of color throughout the gemstone is what makes an emerald, sapphire or ruby most desirable. As with diamonds, a gemstone’s clarity has to do with the number, size and position of inclusions that it contains. The fewer, smaller and less conspicuous the inclusions, the better—but remember their presence reflects the gemstone’s fascinating origin.

Vivid green, with a lot of depth, is the most desirable color for an emerald. And it’s said that emerald green should be the perfect balance of blue and yellow—but the appraisal and appreciation of color is subjective. As always, a gemstone with greater transparency is regarded as superior. It is extremely unusual to find a perfectly ‘clear’ emerald. Almost all contain inclusions that are visible to the naked eye. These may be embedded crystals of other minerals, growth lines, cleavages or tiny fractures. They are entirely natural, and indeed tell the story of the gemstone’s origin. Richly included emeralds possess their own kind of beauty—some of their patterns are so intricate they are referred to as an emerald’s ‘jardin’.

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Sapphires come in a wide range of colors, and each of these has its own quality variation whether blue, pink, purple, yellow, green, orange, or padparadscha, which is a salmon color. Depth of color has the most important influence on a blue sapphire’s value. Sapphires having a strong to vivid velvety-blue color saturation are most coveted, but with saturation too intense, depth of color compromises the brightness. Blue sapphires with extremely high clarity are rare and very valuable. Several types of inclusions are found in sapphires. Among these are long thin mineral inclusions called needles; fine needles are called silk when they occur as the mineral rutile in intersecting groups.

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The most prized color for a ruby is a vivid crimson with a hint of blue, but often they are more violet or pinkish than a true red. As with all gemstones, the color should be even throughout. Rubies from different origins often have distinctive colors—Mozambican rubies, for instance, are a deep pink hue. It is rare to find exceptional clarity even in high-quality rubies. Look instead for a gemstone with good transparency—that is, an ability to transmit light. Still, a good-quality ruby should not have inclusions that are distractingly obvious. Nor should there be so many that the gemstones appear dull. A ruby that is relatively free of inclusions will have lots of brilliance and sparkle. This is important if the gemstone is faceted—though less so if it is a cabochon, in which case the color is most important.

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Transparency refers to the ability of a gemstone to transmit light. The quantity or absence of opacity determines what is called a stone's brilliance. Unlike diamonds, colored gemstones do not have a universal grading system. Professional jewelers do however tend to grade precious gems using the following:

Natural AAA
few inclusions with high brilliance.
Natural AA
moderately included with a bright, even hue.
Natural A
heavily included and opaque; dark in color.

Diamond School

Semi-Precious Gemstones

We appreciate the rosy sparkle of peach morganite and the otherworldly fire of rainbow moonstones as much as we do the glittering beauty of a white diamond. Each holds its own alchemical power and allure. Seeking out stones of the highest quality available, we offer an inspired assortment of semi-precious gemstones including many that are certified single origin.

Coveted for its kaleidoscopic flashes of radiant color, the opal is a rare beauty. With a name derived from the Greek word opalus, meaning “to see a change in color,” the stone’s chameleonic properties have inspired many ancient cultures to deem it magical. Though all opal is comprised of silica and water, there are a number of varieties from Australian white, black and matrix opal to fire opal and Peruvian or blue opal from Central and South America, boulder opal from the western United States and Welo opal from Ethiopia.

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Turquoise has long been treasured by people the world over and appears in the jewelry and precious artifacts of many ancient civilizations. The elaborate gold and turquoise bracelets of Queen Zer of Ancient Egypt are the earliest known jewelry forms dating to 5500BC. Native Americans of the Southwest have been using Turquoise since the Ancestral Pueblo tribes made Heishe beads, and the various tribes continue today with the iconic silver and turquoise jewelry first created in the 1850’s. Turquoise is a stone of communication and mental clarity. We work with specially sourced Turquoise, exclusively in our Future Heritage Collection.

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Morganite is the pretty, peachy-pink variety of beryl—others include emerald and aquamarine. Its feminine colors result from the presence of manganese. After its discovery in California and Madagascar in the early 20th century, this pink beryl was renamed morganite in honor of financier and gem enthusiast J. P. Morgan. Though there are also small deposits in Brazil, Mozambique, Namibia, Afghanistan, and Russia, quality morganite remains relatively rare. It has many important qualities, including durability, luster, clarity and brilliance.

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A perfect balance of beauty and imperfection, rutilated quartz is the result of mineral inclusions caught within a clear quartz crystal. Ranging from golden to coppery, these highly refractive, delicate needles look most beautiful streaking sparsely through sections of the quartz. Like quartz with rutile, this stormy gemstone is a result of black tourmaline encapsulated within the quartz crystal. It is a powerful gemstone associated with the energies of both the consciousness-raising quartz, and the protective qualities linked to black tourmaline.

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The moonstone was so named for its otherworldly luminescence, a trait caused by light diffraction among the varying feldspar layers of its mineral formation. Used in jewelry throughout antiquity, both Greeks and Romans associated the glowing gem with lunar deities, while in India the silvery stone is a symbolic one for lovers. Moonstone occurs in a variety of muted tones from white and peach to blue and grey, while rainbow moonstone refers to the color that is both white and laced with a prismatic sheen.

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Spinel is a natural gemstone which has, throughout history, often been confused with Ruby in its red iterations. Spinel comes in a vast range of colors, most notably a brilliant red and deep, cobalt blue. They can also be grey, which is neutral but accompanied by a gorgeous blue tint. Sometimes Spinel are pastel-colored in lavender, mint green or pale pink and blue. Their fine colors can give Ruby and Sapphire a run for their money, even surpassing their richness of color. Uniquely, Spinel often has a high level of fluorescence, meaning it fluoresces in sunlight creating a glowing effect.

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Diamond School

Precious Metals

Our fine jewelry and ceremonial rings are available in platinum, 14 karat or 18 karat gold—a karat (k) being the measure of purity. Pure gold is 24K, and any number below that means that other metals are mixed with the gold to form an alloy, which renders the material durable enough for daily wear. The gold that we use is entirely recycled; one of the many choices we make to create a more sustainable collection.

The defining features of gold purity are the richness of the yellow color and the relative softness of the metal (pure gold being very soft). The more the gold is alloyed, the stronger, and more lasting it becomes. Simultaneously the color of the gold changes, making a 14K more of a soft buttery yellow compared to the richer pollen color of 18K.

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Perfectly pastel, rose gold results from copper being mixed into a yellow gold alloy. We work with both 18K and 14k rose gold, which is light pink. Our 18k version is more of a peachy hue, which was custom blended to achieve the beautiful ‘Tea Rose’ color, and can be seen mostly in our Flying Flowers fine jewelry collection.

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We love the timeless look of white gold with white diamonds, and how this elegant metal allows the stones to really shine. We offer white gold in 14K, which is always coming with a white rhodium finish to elevate the white color. Note: The rhodium will wear off over time, but it is easily reapplied.

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All of our rings can be made in platinum, on request. Platinum is both highly valued and the most durable of the precious metals; it is also slightly heavier and more expensive than gold. The color of platinum is purely white, as opposed to white gold, which is an alloy of yellow ore and requires a rhodium finish.

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A cascade of wedding bands and an engagement rings on a pink background

Diamond School

Ceremonial Bands

Whether beautifully bare or diamond dusted, our curved nesting rings meet in infinite combinations inviting you create a look uniquely your own. A single band looks delicately minimal, while layering colors of diamonds and seed pearls creates an effect of luster and luxe.

The Tiara Collection

An icon of our ceremonial bands collection, the Tiara series of diamond and gemstone bands is gracefully curved to fit around the center of an engagement ring. Available in myriad variations—from the truly regal Marquise Tiara to the wide sweep of the Tiara Curve—they work with everything from round or cushion cut to linear, emerald cut stones, and even sit beautifully with three stone styles.

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The Curve Collection

The subtle beauty of the Curve band looks elegant worn stacked and nested, wave-on-wave, or as a single, delicate contour. Set with diamonds or adorned in luminous seed pearls, our range of Curve bands shimmer in smooth gold that inspires a sense of wonder at simple, organic lines.

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The New Moon & Crescent Collections

Diamond dusted and infinitely delicate, the New Moon and Crescent bands, like their namesakes, lend an air of mystery and illumination. Each is available in two sizes designed to sit perfectly against a solitaire stone, as well as stacked to create a double halo radiating out from the ring.

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The Geometric Collection

Sharp lines give an elegant edge to any ring stack, but these shapes are also striking worn singly. Designed to sit perfectly against the point of a marquise or pear-shaped stone, these bands—which include the Chevron, Celestine Tiara, Orbit and Chrysalis bands—also make an unusual statement paired with a round stone, or nested by size within each other.

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