May Birthstone Emerald: Origins, Oil & Seven Eras
Emerald is May's birthstone on the modern American list, the traditional list before it, and the British list of 1937. No Western tradition dissents.
The inclusions inside an emerald are called the jardin. Their total absence is a reason to suspect glass.
More than ninety percent of emeralds on the market have oil or resin drawn into the fissures that reach their surface. Emerald is the only gem where the trade expects it.
The emerald cut exists because emerald breaks. Broad flat facets and cropped corners take away the points where a brittle stone chips during setting.
In 1904 cabochon cutting was all but unknown for emerald in Europe. Twenty years later the sugarloaf cabochon was an Art Deco signature.
The Roman encyclopedia Natural History, finished in 77 CE, ranked emerald third among all gems, behind diamond and pearl. The reason had nothing to do with rarity or hardness. Emerald was the one gem that rested a tired eye, a claim already three centuries old when the Romans repeated it.
Emerald is the most fragile of the great colored gems, and most of what makes it interesting comes from that.
- What Is the May Birthstone?
- Why Have Emeralds Been Prized for Two Thousand Years?
- Where Do the Best Emeralds Come From?
- How Is Emerald Color Graded?
- What Is the Jardin in an Emerald, and Is It a Flaw?
- Are All Emeralds Treated with Oil or Resin?
- Why Is the Emerald Cut Named After the Stone?
- How Did Emerald Jewelry Change Across the Eras?
- Can You Wear an Emerald Every Day?
What Is the May Birthstone?
Emerald is the May birthstone on the modern American list, on the traditional list before it, and on the British list of 1937. No major Western tradition gives the month to anything else.
That agreement is rare. American jewelers met in Kansas City in August 1912 to set the first standard list, and some months changed. March dropped bloodstone, which had held the spot for centuries, for aquamarine, and August moved peridot ahead of sardonyx. May needed no swap. Emerald had held it in Europe for as long as anyone had been giving stones to months. The one list that disagrees is the mystical or Tibetan list, which reached the West in the 1980s and puts emerald in January.
Emerald is the green form of beryl, colored by chromium and in some deposits by vanadium. That makes aquamarine its sibling: same mineral, different trace element. Colombian stones run about 0.186 percent chromic oxide. Fuse white glass with that same small dose of chromic oxide and the green matches a fine emerald, a test that dates to 1904.
George Frederick Kunz, who did more than anyone to fix American birthstone practice, gave May a full sentiment package in 1913. The guardian angel Amriel, the sign Gemini, the flower hawthorn, and two verses promising a happy marriage to any May-born woman who wore the stone for life. The seasonal note is better: nature clothes herself in green when she wakes from her long winter rest, he wrote, and then sets that green behind the first spring flowers. On the birthstone jewelry guide emerald also carries the 20th and 55th anniversaries, and its nearest company in the trade is ruby and sapphire.
Why Have Emeralds Been Prized for Two Thousand Years?
Emerald's standing rests on one claim, written down before 300 BCE: the stone was good for the eyes. Gem engravers were said to keep one on the bench and rest their sight on it between jobs. Nothing else in the ancient record was given a use like that.
Nero owned the most famous example, and it is usually described wrong. The Roman account says he watched gladiators through a flat, reflecting emerald. A flat stone corrects no vision, so the story that he beat eyeglasses by a thousand years does not survive the description itself. Cutting glare through a color the eye finds easy is the simpler answer.
The hard evidence starts in Egypt. Two groups of workings sit in the Eastern Desert, Jebel Sikait and Jebel Sabara. Some galleries held four hundred men at once, and tools found in them date to about 1650 BC. Greek miners worked them under Alexander, and Cleopatra is said to have sent emeralds engraved with her own portrait as gifts of state. The mines were lost for centuries afterward, until a French traveller walked back into them in the early 1800s and found the veins worked out.
Where Do the Best Emeralds Come From?
Colombia has set the standard since 1558 and still does. Zambia, Brazil, and a set of Asian deposits each give a different green.
Emerald is the one precious stone found only in the rock where it grew, never washed loose into river gravel. Colombia then breaks even that rule. Instead of the mica-schist that holds emerald elsewhere, Colombian crystals sit in calcite veins running through black Cretaceous shale and limestone. Europeans learned the source on March 8, 1537, when Indigenous people handed emeralds to the Spanish and pointed toward Somondoco, and mining at Muzo began in 1558. Muzo green runs a little yellow, Chivor runs bluer, and Coscuez and Gachala each have a look of their own. Muzo's fingerprint is parisite, a rare cerium fluocarbonate, listed among the mine's minerals a century before it became a routine origin marker.
Zambia is the modern rival. The Kafubu and Miku deposits run high in iron, about 0.73 percent, which pulls the green cooler and bluer. Tremolite rods and biotite plates are the Zambian tell. Brazilian stones from Bahia, Minas Gerais, and Goias tend lighter and bluish. As late as 1904 the standard gem text denied Brazil had any emerald at all and blamed green tourmaline for the mix-up. Sandawana in Zimbabwe was found in October 1956 by Laurence Contat and Cornelius Oosthuizen. It yields deep green stones, oddly clean for emerald, almost all under a quarter carat. The Urals turned up in 1830, one account crediting a man burning charcoal, another a peasant who spotted green stones in the roots of a wind-thrown tree.
Then the Asian deposits: Rajasthan in 1947, Pakistan's Swat Valley in 1958, Afghanistan's Panjshir Valley in 1977, Davdar in Xinjiang in the 2000s. Three-phase inclusions, tiny cavities holding gas, liquid, and a crystal, were taken for decades as proof of Colombian origin. Panjshir and Davdar stones have them too. A Gallo-Roman earring dug up in France holds an emerald whose oxygen isotopes match Swat Valley in the first century CE. Asian emerald reached Western Europe long before the medieval period lost track of it.
How Is Emerald Color Graded?
Color carries an emerald further than clarity does. If you have shopped for a diamond, that is the reverse of the order you learned.
Labs describe color on three axes: hue, tone, and saturation. Hue is which green it is, and it is never only green. It leans a little blue or a little yellow, and the lean is the first thing to look for. Tone is how light or dark, running from pale to nearly black. Saturation is how much color is present, as against gray. Saturation does the most work and is the hardest of the three to judge on a screen. A gray-green stone and a vivid green stone can photograph as the same green.
Here is why the order flips. A diamond is graded against an ideal of nothing: no color, no inclusions, and every step away from that counts against it. An emerald has no such ideal to fall short of. It is expected to be included, so clarity stops being a ranking and turns into a description. What is left to separate a fine stone from an ordinary one is the green itself. A heavily included stone in a vivid medium green reads as the better emerald over a cleaner stone in a weak one. That one sentence undoes most of what a diamond buyer walks in with.
The named origin greens describe hue and tone. They are not grades. Colombian green means a medium to medium-dark tone with vivid saturation and a hue sitting at pure green or a touch warm, which is what Muzo material tends to do. Zambian stones lean cool and blue, from the iron noted above. Brazilian stones tend lighter. None of that is a quality claim on its own. A weak Colombian stone and a fine Zambian one both exist, and the report describes the color either way.
Three things can go wrong that a color grade will not tell you. Color zoning means the green is not spread evenly, and it shows as bands or patches, often running across the crystal's flat top. Windowing means the stone is cut too shallow, so you can read print through the middle of it and the green thins out there. Extinction is the other way around: a stone cut deep or toned too dark goes flat under low light, which is where a ring spends most of its life. Take a dark stone out of bright light and look at it in a room with one lamp. That is the test.
Two labs can describe the same stone differently, and that is not a scandal. Color is graded by eye against master sets under controlled light, and the wording is the lab's own. One report may read vivid green and another intense green for the same stone. Compare descriptions from the same lab where you can, and give more weight to what you see in your hand than to the adjective. Keep two things apart as well: a color grade is not an origin report. Origin is worked out from inclusions and trace elements and issued as its own document, and a stone can carry a Colombian origin report and a middling green.
Filigree's emerald pieces cover that range. Some stones are described as sea green, cooler and lighter. Others are a deep saturated green. A few carry GIA reports naming Colombian origin, and others are Zambian. Sizes run from under a carat to past ten. Reading two of them against each other is the fastest way to learn what tone and saturation mean, because the words only land once you have seen the difference.
What Is the Jardin in an Emerald, and Is It a Flaw?
An emerald with no flaws at all is the one to worry about. Glass copies emerald better than any other gem, and by 1865 a flawless emerald was itself grounds to suspect paste. An emerald without a flaw was a period proverb for a thing that does not exist. The flaws have a name: the jardin is the network of fissures, fluid pockets, and foreign crystals inside almost every emerald.
GIA files emerald as a Type III gemstone, its shorthand for stones that are nearly always included. An eye-clean emerald is a rarity, not a standard the market keeps missing. Most crystals come out clouded by fissures, cracks, and inclusions too small to see without a loupe, which among precious stones is unique to emerald. The old trade word for the cloudy ones was mossy.
A first-century list of the same features survives. It describes stones crossed by a shadow, which dulls the color. Stones it calls blind, because they are opaque, and stones wrapped in a cloud. Then filaments, specks like salt, and inclusions that look like lead. Those map onto what we now call jardin, silk, clouds, and color zoning, almost word for word.
Read the right way, the jardin is an address. Parisite points to Muzo, tremolite rods and biotite plates to Zambia, fine tremolite needles to Sandawana, phlogopite mica to the Urals. The inside of the stone is its provenance record, which is why a cutter will sometimes feature it. One 6.79-carat rough crystal came up from the Nuestra Senora de Atocha, the Spanish galleon that sank in 1622. The carver Meg Berry cut it to 2.08 carats and turned it to leave the pattern in plain view.
The rarest thing an emerald does inside is the trapiche. Black carbon inclusions radiate out from the center of the crystal and split it into six sectors that read as a fixed six-pointed star. The name comes from the spoked wheel used to grind sugar cane. Trapiche stones are Colombian, limited to Muzo, Coscuez, and Penas Blancas, and found in a very small share of production.
Are All Emeralds Treated with Oil or Resin?
Nearly all of them are, and emerald is the only gem where the trade expects it and says so. GIA puts the figure above ninety percent of the stones on the market.
The reason is optical. The stone comes out of the ground with fissures that reach the surface, and a fissure shows because light scatters where it crosses from stone into air. Draw a colorless liquid or resin into that gap under vacuum and the two sides of the wall move closer in refractive index. The scattering drops. The fissure stops announcing itself.
Only the cracks that reach the surface can be filled. The filler has to get in from outside, so a flaw sealed inside the stone stays as it is.
The numbers are where the estate market parts from the modern one. Cedarwood oil, the old filler, sits at 1.512. During the 1990s the trade moved to Opticon resin at 1.545, much nearer emerald's own 1.569 to 1.602, and the masking got sharply better. So an antique stone's filler is chemically different from a modern one's, and the two age differently. Oil migrates, dries, and needs replacing. Hardened resin stays put, which is why the trade counts resin as the bigger treatment of the two.
Oil and resin are not the same deal, and the trade does not treat them as one. Cedarwood oil comes back out. Warm the stone, or leave it long enough, and the oil goes on its own. Resin sets hard and stays, and getting it out takes a specialist working with solvents. So oil reads as upkeep, and resin reads as a change made to the stone. That is why a report naming resin gets read more slowly than one naming oil.
The degree is on the report, and worth asking about. Labs write it as FF-O, fissure filling with colorless oil or resin, graded 1, 2, or 3 by how much filler the stone took. A stone that needed very little is a different piece from one that needed a great deal at the same color and clarity. Green-tinted oils and resins are a separate matter, and the trade does not accept them. A tinted filler adds color instead of clearing the stone.
The same amount shows up elsewhere as a plain word scale: none, minor, moderate, significant. Read it as a description, not a verdict. None means the cracks are dry and nothing stands between you and the stone, which is rare. Minor means a light fill on a stone that came out fairly clean. Moderate means the filler is doing real work and you are seeing a cleaner stone than the rough was. Significant means it is doing most of the work, and if it ever leaves, the look changes with it.
Treatment has to be disclosed, and a report from a working lab says so plainly: the species, whether the stone is natural, and the type and degree of filler. Estate stones are the harder case. A ring from 1925 has passed through a century of owners, cleanings, and repairs with no paperwork behind it. Ask what is knowable instead. Has the stone been out of its mount and examined? Does the filler read as oil or as resin under a microscope? Was it re-oiled before the piece was offered, and when?
This is also why the stone gets cleaned by hand. Ultrasonic cleaners, steam, and boiling water all strip filler, and once it is gone the fissures underneath show and are open to damage. Warm water, mild dish soap, and a soft brush handle routine cleaning, and the jewelry care guide covers the rest by stone type. Re-oiling every few years is upkeep, not repair.
Filler is not permanent. Oil dries out over years, and it leaves quickly when it meets something it should not: an ultrasonic tank, steam, hot water, a solvent, or the heat of a torch during a repair. A stone that has lost its oil is not damaged. It looks like what it always was, and it can be filled again.
None of this is new. A sixth-century note on the foundation stones of the New Jerusalem describes emerald as green in color and nourished with oil, so that its clarity would not change. The practice is at least fifteen hundred years old. Only the chemistry has moved.
No other stone in the top tier lives this way. On a fine ruby or sapphire, filler counts against the piece. On emerald it is the baseline, because emerald comes out of the rock already cracked and there is no version of this trade where most of it goes unfilled. So the treatment line on the report carries as much weight as the color line.
Why Is the Emerald Cut Named After the Stone?
The emerald cut exists because emerald breaks. Broad flat facets and cropped corners are damage control, and the four cut corners take away the four points where a brittle stone chips while a setter tightens it.
Emerald rates 7.5 to 8 on the Mohs scale, which sounds like plenty and answers the wrong question. Hardness is about scratching. Toughness is about chipping and fracture, and emerald's is poor. Cleavage indistinct, fracture brittle, and the stone already fissured before anyone touches it. Muzo material had a stranger problem still. Some crystals came out of the mine clear, then grew fissures and clouded over. Others held cross fractures filled with thin calcite, looked whole in the rock, and fell apart once freed. Miners tried sealing fresh stones in closed boxes to dry them slowly. It seldom worked.
The step cut answers all of that at once. Broad parallel facets put stress nowhere, and shallow angles take less off a stone that has little to spare. And the cut corners hand a setter four blunt shoulders instead of four sharp points, which decides whether a stone survives being tightened. European practice in 1904 followed the same logic, with step cuts and plain table cuts as the norm. Brilliants went to faultless fragments, pale stones were foiled underneath, and faulty ones went into closed settings blackened inside.
Then the name traveled. The shape works so well on a rectangular outline that it was adopted for diamonds and for all the others. So an emerald cut engagement ring almost always holds a diamond in the emerald shape, not an emerald. The stone and the shape share a name and nothing else.
Mughal lapidaries solved the same problem from the other end. Tavernier records emeralds left as cabochons or given plain table cuts to keep weight and color instead of chasing brilliance. He also records large stones drilled through for stringing, which European jewelers called destruction. One of the finest emeralds ever found was drilled through the center so it could sit on Ranjit Singh's arm.
How Did Emerald Jewelry Change Across the Eras?
Emerald's design history is set by its limits. Each era used the stone in whatever form its cutting and setting could support without wrecking it.
Georgian (1714 to 1837). Georgian emeralds kept the older forms, table cuts and simple step cuts. Complex faceting on a stone that much softer than diamond was a risk, and Georgian taste wanted depth of color over brilliance anyway. Settings were closed-back collets, each stone in its own metal cup, often with foil beneath. That was built for candlelight, where an open back would let the color wash out. The emeralds that survive in Georgian pieces are usually pre-Peruvian Eastern stones, harder, deeper in color, seldom bigger than a hazelnut. Georgian jewelers also gave us acrostic jewelry, where the first letter of each stone spells a word. Emerald is the E in both formulas. REGARD runs ruby, emerald, garnet, amethyst, ruby, diamond. DEAREST runs diamond, emerald, amethyst, ruby, emerald, sapphire, topaz. The form began here and peaked under Victoria, so most acrostic rings that survive are Victorian. Emerald sits in nearly every acrostic ring across two eras. A Smithsonian pendant of 1775 to 1825 mixes emerald with agate, onyx, gold, and enamel.
Victorian (1837 to 1901). The Victorian emerald story starts with a ring. Around 1839 Prince Albert gave Victoria a serpent ring set with an emerald, her own birthstone, the snake swallowing its tail for eternity. Serpent jewelry spread across the period from there. In Rome and London the archaeological revival used emerald another way. Fortunato Pio Castellani and Sons stuck to stones the ancients could have had. They set carved emeralds in cast and woven gold with enamel and pearls, using granulation worked out by studying Etruscan pieces. A Smithsonian necklace of about 1880 to 1900 and a Castellani bracelet of about 1880 both survive. Reinhold Vasters made Renaissance-revival work in enameled gold with emeralds and rubies, good enough that museums catalogued it as sixteenth-century. His Triton pendant of about 1870 to 1895 sits at the Metropolitan Museum. Later Tiffany and Co. made an emerald, diamond, and platinum brooch around 1900, and Marcus and Co. a gold, diamond, and emerald double ring around 1895, both showing the move into platinum that Edwardian design would finish. By 1877 sapphire had supplanted emerald in general esteem, a swing put down to fashion and to supply being held back or released.
Art Nouveau (1890 to 1910). Emerald was an accent here, not a center. The Art Nouveau dragonfly, borrowed from Japanese design, needed small saturated green stones for eyes, and emerald competed with demantoid garnet for the job. The era's taste for opal, moonstone, baroque pearl, and horn left little room for a stone whose whole appeal is color.
Edwardian (1901 to 1915). Edwardian work was all white: platinum, diamond, pearl, openwork fine enough to read as lace. Colored stones were rare, and emerald rarer than sapphire. When it did appear it was often calibre-cut, each stone ground to fit its own slot in the platinum rather than picked from stock. Emerald took that grinding badly, which is much of why Edwardian emerald pieces are scarcer than the sapphire ones.
Art Deco (1920 to 1935). Here is the real break, and the sharpest fact in emerald's design history. In 1904 cabochon cutting was all but unknown for emerald in Europe. Twenty years later the sugarloaf cabochon, a domed emerald with no facets at all, was a signature Art Deco center stone. The Victoria and Albert Museum holds a Cartier example from the 1920s. A rule that had held for centuries reversed inside one generation. Muzo and Somondoco supplied the deep green that anchored the era's color schemes. Carved emeralds in leaf and berry forms drove Cartier's Tutti Frutti pieces, most of them older Mughal stones recut after they reached European markets through colonial trade. The Maharaja of Patiala brought his own stones to Boucheron at 26 Place Vendome in the 1920s to have them reset. Calibre-cut emerald in platinum channels shows up too, and it marks top work because of the waste. The rough was cut to fit the setting rather than to hold weight, so a lot of stone was ground away to fill a channel with unbroken green. Filigree's Art Deco pieces show both ways of doing it, the bezel-set single stone and the calibrated field.
Retro (1935 to 1950). Emerald nearly vanishes, and the reason is physical. Retro design wanted big, durable, boldly mounted stones in gold, and emerald is brittle and seldom clean at scale. Aquamarine took the job, because flawless clear aquamarine is far less rare. Retro aquamarines run 20 to 40 carats in cocktail rings that could not have been built in emerald. The exceptions sit at the top of the market. Verdura's Maltese cross brooches set cabochon colored stones at the terminals with pave diamonds at the crossings. The original pair, made for Coco Chanel, used Chanel's own emeralds and rubies.
The most demanding setting technique of the century simply excluded the stone
Mid-Century (1950 to 1970). Cabochon emerald comes back, now as one color among many. Bulgari broke the French habit of matched single-stone suites, putting cabochon emerald with sapphire, amethyst, and tourmaline in one piece, all domed for saturation and mass rather than faceted for fire. That Dolce Vita approach treated color as a thing to compose with. David Webb used cabochon emerald for the eyes of carved coral and jade animal bangles in hammered gold. Jean Schlumberger set emeralds and sapphires with diamonds and platinum in a brooch of about 1960, now at the Victoria and Albert Museum. And the era gives us the reverse case. Van Cleef and Arpels' mystery setting, patented in 1933, grooved each stone along two edges so it could slide onto a hidden gold rail. No metal showed, just an unbroken surface of color. It was the most demanding setting technique of the century, and it went to ruby and sapphire, never emerald. Emerald fractured under the groove-cutting.
For dating an estate piece, that history is useful. A sugarloaf cabochon emerald is a post-1920 idea. A calibre-cut emerald channel is high Art Deco and scarcer than the sapphire version of the same work. A closed-back foiled collet is Georgian. The stone's limits left dates on the metalwork, and the emerald collection carries examples across the range.
Can You Wear an Emerald Every Day?
Yes, if the setting protects it and you accept that the stone needs upkeep. That is not the same as a sapphire or a diamond.
An emerald shrugs off scratching. What hurts it is impact against a hard edge, because the fissures already inside are where a knock travels. An 1877 account put it this way: emerald color loses some of its intensity with long use. The Spanish colonial hammer test took the same error all the way. Convinced a real emerald would survive a blow, testers smashed real stones to prove them real, including a revered stone in the Manta Valley that Alvarado's followers broke to pieces.
So the setting answers this question more than the stone does. Two rings can hold the same emerald, and one will come through a decade of daily wear while the other chips inside a year. The difference is how much of the stone is left standing out in the open.
A bezel is the right answer for a ring worn every day. The metal wraps the girdle, the thin edge where the top of the stone meets the bottom, and the girdle is where a knock lands and where prongs leave a stone bare. A half bezel does most of the same work. It covers the two long sides and leaves the ends open so more light gets in. On a step-cut stone the half bezel is often the better looking of the two, because it keeps the corners covered and the flat top clear.
A halo works from the outside in. A ring of small diamonds set around the center stone sits a hair higher than the emerald's edge, so a hard surface meets the diamonds first. Shoulders that rise toward the setting do the same job from the sides. What to avoid is the opposite build: tall thin prongs holding the stone high off the finger with sharp corners hanging past the metal. That profile exists to show a stone off. On emerald, the corners go first.
Then match the piece to the risk. Pendants and earrings take almost no impact, which makes them the safest way to wear emerald daily. A ring on your dominant hand takes more abuse in a week than a pendant takes in a year. So the more fragile stone, or the one carrying a heavier fill, belongs in a pendant or a pair of earrings. Save the tough, lightly filled stone for the ring.
Estate emeralds turn up in a narrow set of mounts, and each one tells you something. Georgian and early Victorian stones sit in closed-back collets, a metal cup with a solid floor, about as covered as a stone gets. Art Deco emeralds are usually bezel set or dropped into a platinum channel, also well protected. The exposed ones are mostly mid-century and later: four claw prongs, a high seat, the whole stone out where you can see it.
With an antique piece the real hazard is not wear. It is repair. Sizing a band, retipping a prong, or resetting a stone means heat, and heat drives oil out of an emerald and can crack the stone outright. Resin takes it no better. So the stone comes out of the mount before a torch goes near it, and the jeweler has to know it is an emerald before starting. That is why a bench jeweler asks what the green stone is before touching the ring.
The habits are short. Put the ring on last and take it off first. Grip, force, and lifting are reasons to take it off. Have the prongs looked at when the piece is cleaned, on a schedule, instead of when something feels loose. And expect to re-oil at some point, the same way you expect to re-tip a prong.
Continue Reading
Emerald Jewelry
Colombian and Zambian stones across rings, pendants, earrings, and bracelets, in Georgian through Mid-Century settings and By Filigree work.
Browse Emeralds →Art Deco Jewelry
The era that put emerald in sugarloaf cabochons and calibre-cut platinum channels, alongside its onyx, ruby, and diamond geometry.
Browse Art Deco →Birthstone Jewelry Guide
The full birthstone calendar, with the stone and the Filigree pieces for every month of the year.
View the Guide →The gem with a garden inside it
Emerald is the gem whose defects were catalogued by name in 77 CE and are still called a garden. It is the one stone the trade agreed to fill rather than hide, and the reason a cut carries its name.
Its design history follows the material honestly. The eras that could protect it used it hard, and the era that could not left it to aquamarine. The emerald collection is where that history is visible in the pieces themselves.
The Emerald Collection
Georgian table cuts through Art Deco cabochons and modern Colombian and Zambian stones, in rings, pendants, earrings, and bracelets.
Tuesday–Friday 11AM–6PM · Saturday 11AM–5PM
May Birthstone Emerald
What anniversary is emerald for?
Emerald marks the 20th and the 55th wedding anniversaries on the standard modern list. The 55th was on record by 1913.
Can emeralds go in an ultrasonic cleaner?
No. Ultrasonic cleaning, steam, and boiling water all strip the oil or resin filling the fissures that reach an emerald's surface. Once the filler is gone, those fissures show and they are open to damage. Warm water, mild dish soap, and a soft brush are the safe method, and the jewelry care guide covers cleaning by stone type.
Is emerald the only May birthstone?
Yes, on every major Western list: the modern American list of 1912, the traditional list before it, and the British list of 1937. The outlier is the mystical or Tibetan list, which reached the West in the 1980s and puts emerald in January.
What is a trapiche emerald?
A Colombian emerald in which black carbon inclusions radiate out from the center of the crystal, splitting it into six sectors that read as a fixed six-pointed star. The name comes from the spoked wheel used to grind sugar cane. The pattern is limited to the Muzo, Coscuez, and Penas Blancas mines, and it occurs in a very small share of production.
Is an emerald cut the same thing as an emerald?
No. An emerald is a green beryl. An emerald cut is a rectangular step cut with cropped corners, worked out to protect brittle emeralds and then adopted for other gem species. That is why most emerald cut rings hold diamonds rather than emeralds.
