About Emerald
Emerald is a gem-quality species of the Beryl mineral family with a rich distinctly green colour. They are found in igneous metamorphic and sedimentary rocks in a small number of locations worldwide. For over 5000 years, emeralds have been one of the most desirable and valuable coloured gemstones and become one of the four most precious stones alongside diamonds, sapphire, and ruby. Emeralds are often categorized by their source, with notable origins including Colombian, Zambian, Brazilian, and Afghan emeralds. Zambian emeralds stand out in the world of gemstones for their exceptional quality which makes it an ideal gemstone for anyone looking to expand their jewellery collection whilst making an excellent investment.
History Of Zambian Emeralds
Zambia is considered the world’s second most important source of emeralds by value (after Colombia). The deposits are located near the Kafubu River in the Ndola Rural Restricted Area. Zambian emeralds have been known there since 1928, However, there was no real interest in mining these deposits until the 1970s to 1980s with developed prospecting and mining techniques. As of mid-2004, most of the emeralds were being mined from large open-pit operations at the Kagem, Grizzly, and Chantete concessions. Since emeralds are so valuable, they are also capable of bringing in a great deal of wealth to Zambia. As a result the national government has continued to be involved in developing and regulating these mines. This has led to a number of international companies, the most notable of which is Gemfields. In 2008 Gemfields claimed an open-pit mine at Kagem that was producing no ore. The entire mine was turned around a year later, becoming profitable and producing over 27 million carats of emeralds. Kagem is now considered to be the world’s largest emerald mine. Nearly all of the rough is cut in India and Israel.
Treatments
Natural emeralds, members of the beryl mineral family, are notably more included than most other gemstones, with these inclusions typically comprising liquids, gases, and minerals. Additionally, the majority of emeralds exhibit small fissures or surface-breaking cracks. Clarity-enhancing treatments are widely practised to improve their appearance and value. This includes treating a stone with oil or synthetic lubricants.
The 4 C's Of an Emerald
Colour
Certainly! In gemological terminology, the colour of an emerald is analyzed through three main characteristics:
Hue – Is the denotation of what most would call the colour of the stone. The primary hue of Zambian emeralds is a rich green but it can be further broken down to distinguish the specific type of green present, whether it includes subtle hints of yellow or blue tones. The presence of yellow undertones can lend warmth to the colour, while blue undertones add coolness and depth to an emerald. Therefore Zambian emeralds, allow collectors and jewellery designers to appreciate the subtle complexities of each gemstone.
Tone – This is a measurement of the lightness or darkness of the Emerald. This is calculated by assessing how much neutral colours of white, grey and black contribute to the overall colour.
Saturation – The first and foremost property of emeralds is judged by their colour. A highly saturated emerald will outprice larger emeralds with less appealing colours consistently, despite the rarity of larger gem sizes. From a scientific standpoint, this is a measurement of the bandwidth of the light returned to your eye from the stone.
CLARITY
Emeralds are known for being included as it is a type 3 gemstone. They almost always have inclusions, which are mineral crystals or cavities filled with fluid and/or gas that occur in a host gemstone. About 99% of all natural emeralds will present these features. The type and frequency of these inclusions are the determining factors in judging the clarity of an emerald. Eye-clean emeralds (inclusions are not readily visible by the naked eye) go for double to triple the price as they are extremely rare and command a substantial premium over their counterparts. However, It is also widely appreciated that inclusions in emeralds can also enhance the look of a stone.
Cut
The cutting of emeralds and other coloured stones is considered as much an art and a science as it significantly influences its overall appearance and value. Unlike the perfectly symmetrical cuts prized by the diamond market, coloured stones are usually cut in a more artisanal fashion. The cut, or how the emerald is faceted, has a lot of complications. First, gem cutters often cut away 50%-70% of the original emerald to get the gem to show its best colour and sparkle and then cut the stone in a fashion that releases the full potential of the rough material. Since these gems are priced by weight in carats, lapidaries aim to retain as much carat weight as possible while optimizing the gem’s beauty and market value. A lapidary also needs to keep emerald pleochroism in mind, since this means the emerald shows slightly different colours of green at different angles. So a superior cut can improve the colour presentation of an emerald, but excessive weight loss during cutting can result in the gem appearing too light.
Carat Weight
Carat weight plays a significant role in determining the value and size perception of an emerald. It is a little more complex since the price increases exponentially with carat weight in emeralds. For example, a 4-carat stone will be more expensive than a 1-carat stone, all other factors being equal. So The colour, clarity, and cut are evaluations of quality, carat weight measures rarity and directly translates that into a price marker.
