May Birthstone: Emerald
14 Minute Read
What is the Birthstone for May?
The birthstone representing May is emerald, a rich green variety of the diverse beryl gem group which must exhibit a dark enough tone and saturation to be called by that name. There is an abundance of both large and tiny gems on the market. Unlike some of the other transparent birthstones, it is perfectly acceptable for emerald crystals to have noticeable clarity characteristics. In a reference to the lush color of the gem, the unique collection of inclusions in each stone is affectionately called its "jardin", the French word for garden.
Emerald is a long-time favorite of royalty, some of whom launched expeditions across land and sea to collect the gem. Today, emerald is set in jewelry that falls in many different price points, ranging from affordable to truly extravagant. The unique and powerful green color of emerald has granted them such high and sustained popularity on a global scale to make them part of an exclusive group of colored gemstones called the Big 3 which also includes sapphire and ruby.
In addition to representing the month of May, the emerald is also traditionally given to commemorate both 20th and 35th wedding anniversaries.
What is the May Birthstone Color?
The most important value factor of emerald is its green color. It is interesting, then, that the definition of color for what it takes for a beryl gem to be called emerald is actually not as well defined as it is for many other gems. As you will often see repeated with regard to colored gemstones, the color of emerald is evaluated based on the combination of three factors: hue, tone, and saturation.
Hue is what we usually think of when someone mentions color and it is the most definitively outlined of the three factors. Emeralds must have a dominant green hue which can be pure, show some blue or a very minor level of yellow. A majority, but not all, of the May birthstone crystals are dichroic, showing more yellow when viewed from one direction and more blue from another. Gems which exhibit a degree of yellow when viewed face-up are typically less valuable than those with green or bluish-green hues. However, every hue has a following of its own and you should select gems whose color appeals to you.
Tone (how light/dark the color is) and saturation (how strongly the hue is expressed) of emerald is extremely important because, if either or both are too light, the gem won't qualify as emerald and is simply called green beryl. Exactly how experts define "too light" can vary a little, but this will not impact you as you shop for birthstone jewelry as only a tiny fraction of gems whose color is extremely close to the limit are in question. Professional grading laboratories like the GIA do not leave anything to chance and keep comparison stones available. The finest emeralds will pair the famous green or bluish-green hue with strong or vivid saturation and medium to medium-dark tone. The color of good quality stones is evenly distributed across the crystal with no noticeable patches or variation.
The coveted color of emerald is caused by trace elements in the crystal structure. Similar to one of its beryl cousins, the March birthstone aquamarine, the presence of iron in emerald will induce blue. The green color is primarily caused by either chromium or vanadium. Generally, higher concentrations of these elements intensify the color saturation of the stone. It can be useful to analyze the chemistry of emeralds because the various deposits often have location-specific chemical signatures. In determining the concentrations of the elements that are present, scientists are sometimes able to tell the broad region where an emerald comes from. This is a nifty trick that does not work for all types of gemstones.
Because the nuances of color have a significant impact on value, you may encounter some trade names which describe specific hue, tone, and saturation combinations. These trade names were selected for the sources whose product typifies the color being described, but it is important to know that they only address the color of a stone and do not guarantee that the gem came from that location.
- Columbian - Emeralds whose color can be described as Columbian represent that ideal combination of a bluish-green hue with strong to vivid saturation and medium to medium-dark tone. This is the famous unrivaled green that some have described as so exceptional that it has no counterpart in nature.
- Brazilian - Many of the Brazilian gems have a notably lighter tone than emeralds from other deposits. They are dark enough to still be called emerald, but their color is a little less intense.
- Zambian - Gems that have a darker tone with more blue in their hue are frequently called Zambian. These emeralds have a distinct appearance that appeals to people who are drawn to cooler colors.
- Sandawana - The emeralds mined in the Sandawana mines located in Zimbabwe were set apart by a number of factors. With regards to color, high levels of chromium induced a very strong green hue.
What is the Meaning of Emeralds?
Having been actively mined for many millennia, emerald is truly one of the most ancient gemstones used as ornaments by humans. Its potentially intense coloration and captivating patterns of clarity characteristics have led to a multitude of legends and lore associated with the mind, body, and spirit. With a universal appeal, it is no surprise that royalty of many cultures were captivated by the stone and spent fortunes to grow their collections.
Green is very much associated with abundance, comfort, and security because it is the color of a bountiful ecosystem. If you are surrounded by green plants, chances are there is plenty of food to sustain you. Perhaps to help us evaluate vegetation, our eyes evolved to distinguish more shades of green than any other color so we can appreciate the many subtle color variations emerald can express. This is why there are so many trade names for such a narrow range of colors. If your eyes are feeling tired, it can help to relax them by gazing at something green for a moment. It comes as no surprise that emeralds are associated with good vision and overall eye health.
Continuing along this theme of healthy eyesight, the theory was developed that the May birthstone could allow one to see into the future, leading to reliable intuition and wisdom. It was also said that emeralds help individuals to recognize truth and uncover deception, especially from a lover. Also, as green is associated with life, wearing an emerald is thought to repel certain serious illnesses like malaria or cholera, and amplify fertility. Ancient Greek and Roman cultures both associated the gem with their goddess of love, beauty, and procreation who was called Aphrodite or Venus.
It is no stretch that the emerald, a beautiful but also rare gem intimately connected with vitality, came to be associated with strong nations. This tradition began with the famous Egyptian queen Cleopatra who was known to be especially infatuated with the vibrant gem which was native to her country. She adorned both herself and her palace with emeralds to demonstrate the power and wealth of Egypt to loyal subjects and representatives of foreign powers alike. It is no mistake that US dollars and some paper money from other countries are green.
Where Do Emeralds Come From?
The first known mined emeralds came from Egypt, possibly being removed from the ground as early as 3500 BCE. Egyptian emerald deposits proved to be abundant and remained the primary supplier to Europe until the sixteenth century. At that point, Spanish explorers became aware of the beautiful emeralds from Columbia which had been used there as jewelry and worshipped in religious practice since the 11th century. They expanded mining operations and brought the exceptional gems back to Europe where they were traded across the continent and into Asia, boosting global awareness and demand.
Today, there are important emerald deposits in multiple countries, but it is a relatively short list. Columbia has remained one of the primary emerald suppliers and the best of its gems are still considered to be the finest in the world. Brazil also has generous deposits including a famous one at Minas Gerais. Mines in the African countries Zambia and Zimbabwe contribute significant amounts of relatively clean gems to the global market. Beyond that, there are emerald mines in places like Pakistan, Afghanistan, Russia, Australia, India, and Madagascar but their output is relatively modest.
Is Emerald Durable?
Emerald could only be part of the Big 3 group if they were strong enough to be worn and loved for many years. That being said, the gem is not as strong as sapphire or ruby so some precautions should be taken to keep your gems looking their best. Emerald has a Mohs hardness score of 7.5-8. This means that its surface is overall very resilient but can be scratched, especially if it is stored improperly and allowed to rub against metal settings or stronger gems like sapphire and diamond.
It was mentioned in the introduction that almost all emeralds have at least some eye-visible inclusions and/or fractures which are collectively called a jardin. These features lend individual gems a unique character and can be beautiful if their distribution is balanced and does not cloud the transparency of the gem. However, they can weaken the structure of the crystal if they are especially numerous. Emeralds with lots of clarity characteristics may be more vulnerable to breakage if they are impacted. Clarity characteristics also might be an issue if the gem is exposed to a sudden change in atmospheric pressure, so you may want to leave valuable jewelry at home if you plan to travel by air. If all other factors are the same, emeralds with fewer clarity characteristics are more valuable than those with more.
To minimize the appearance of clarity characteristics, it is very common for emeralds to be "fracture filled" with specialized colorless oils or resins. Some estimate that 90% of the gems you will see have been fracture filled. Fractures become significantly less apparent when filled in, making the gem look cleaner with a more even color distribution. This is considered an acceptable practice and sellers are required to disclose if their inventory has been treated. Most gemological laboratories will issue reports with three standardized descriptions that describe the level of filling as "minor", "moderate", or "significant".
While fracture filling with a clear substance is relatively standard, green fillings have also been developed. Fracture filling using green substances changes the color of the gem. Because the natural color of an emerald has such a significant impact on its desirability, the use of colored fillers is considered by most to be an unacceptable process.
The safest way to clean any emerald is to use a mild soapy water with a soft brush. You should never put emeralds into ultrasonic cleaners or use a steamer as these can cause harm to the clarity characteristics and fillers.
How to Buy Emerald Jewelry
The oldest emeralds ever found are almost 3 billion years old. While gems should be worn with care, surviving so long in the Earth means that they are certainly strong enough to be set in jewelry and enjoyed regularly. Emerald earrings, pendants, and necklaces all have a very low risk of damage so you can wear them whenever you like.
You can easily maximize the lifetime of emerald bracelets and rings by being smart about when you remove them. If you know that there is going to be a heightened potential for rubbing or impact (like when playing sports), or that your hands will be exposed to chemicals (when using cleaning products), it is advisable to set your jewelry aside. Although you do need to be aware of when to wear emerald jewelry, the inherent beauty of the May birthstone makes the extra thought worth it!
Interestingly, the emerald crystal does not have a weak direction and can be manipulated by cutters from any angle. This means that you will see emeralds fashioned into all types of cuts from round to heart-shaped and everything in between. Gems may be cut into tiny sizes, weighing a fraction of a carat, while fine jewelry may have hefty gems. For most jewelry, if an emerald is a primary feature in a design, it will commonly weigh between one and five carats.
The most popular cut for emeralds is the famous emerald cut which features large, polished surfaces with a minimal number of parallel straight facets. This cut is perfect for emeralds because it does not require excessive cutting, allows the viewer to see deep into the gem without confusing reflections, and makes the most of the famous green color. The symmetry here is important to make gems appear balanced so look for a well-cut stone.
Frequently Asked Questions About Emeralds
Emily Frontiere is a GIA Graduate Gemologist. She is particularly experienced working with estate/antique jewelry.
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