Emerald is, without a doubt, the best known of the green gemstones, and the only green gemstone that is considered “precious”. It is the birthstone for May and has grown in popularity over the past few years as jewellery trends have moved towards coloured gemstones. Peridot, tourmaline and tsavorite are all other varieties of green gemstones too, but these are all considered semi-precious gems and aren’t as well known as emerald.
What makes emerald special?
Emeralds are part of the beryl family, a mineral family that also includes semi-precious gems like aquamarine and morganite. When it comes to gemstones and the origins of their amazing range of colours, everything comes down to chemistry.
The prized green colour in emeralds is a result of trace amounts of chromium and vanadium incorporated into the crystal structure. Whilst South Africa is neither known for, or associated with emeralds (generally speaking), our rainbow country is actually home to the oldest emeralds in the world. The world’s oldest emerald deposit is located in our Limpopo province and scientific analyses have dated some of these samples at 2.97 billion years old.
Records of the world’s first emerald mines can be traced back to approximately 330BC, in Egypt. Here, Cleopatra didn’t just cherish diamonds, but even went as far as to claim ownership of all emerald mines in Egypt during her reign.
Historically, Colombia has been one of the most notable sources of emeralds, but in recent years Zambia has become a very significant source. Madagascar, Zimbabwe and Ethiopia are other African countries currently producing gem quality emeralds.
The word’s largest emerald mine is Kagem mine, in Zambia, and it stretches over an area of approximately 41 square kilometers. In 2018, a massive 5655ct emerald crystal was unearthed at Kagem mine. You can take a look at this remarkable specimen here.
Emeralds can range in colours from a pale light green to a deep rich green. Often, emeralds will exhibit different colour undertones, from yellowish to blue. Experts are divided as to which shades of green are more valuable, but typically emeralds exhibiting an intense green-blue colour are considered the most prized.
Natural inclusions and imperfections are common in emeralds and this naturally influences the toughness of the stone. According to Moh’s Hardness Scale, emeralds have a hardness of 7.5 to 8 but they are considered fragile and if you own any emerald jewellery, extra care should be taken when wearing it.
What should you look for when buying emeralds?
When purchasing emeralds, look for emeralds that have even colour distribution (no obvious lighter or darker patches) and, if you can afford it, stones that are “eye clean” (no inclusions visible to the naked eye). The more included or imperfect an emerald is, the more susceptible it will be to breaking or cracking.
Like most coloured gemstones, emeralds are typically laboratory treated to enhance their appearance. Oiling is a common technique used to fill fractures and improve the apparent clarity of the gem.
Not only is emerald the birthstone for May, but it’s also the gem of the 20th and 35th wedding anniversaries and has also been popular as an engagement ring gem. So, if your birthday is in May or you’re celebrating a big wedding anniversary, why not contact us and have a celebratory piece of jewellery manufactured especially for you, or select a piece from our pre-made range?