Emeralds are the most valuable variety of the Beryl group of silicates mined in various geological settings throughout the five continents.

Fine quality Emeralds can cost much more than diamonds of the same size, and like all coloured gemstones, Emeralds are graded using four basic parameters of the four C’s: colour, clarity, cut and carat weight. A fine emerald must have a pure green hue, but also a high degree of transparency.

The intense green colour that has given Emerald gemstones their status as an important gemstone throughout the centuries is caused by trace amounts of chromium, vanadium and iron. For example Colombian emeralds get their colour primarily from chromium while Brazilian emeralds get their colour from vanadium and Zambian emeralds from iron which gives them a bluish or a yellowish appearance. When pure, Beryl is a colourless mineral known as “goshenite”. Trace amounts of chromium or vanadium in the mineral is what causes it to develop a degree of green colour much argued by experts (i.e. gemmologists and gemmological laboratories) about what makes a Beryl an Emerald.

Regardless of their country of origin, Emeralds are beautiful and valuable gemstones with good level of fire and brilliance which makes them ideal gemstones for most types of open setting jewellery, be it a large (cocktail) ring, pendants or a tumbled jewellery. A fine Emeralds with a good green hue, clarity, cut and weight from Zambia or Brazil can command higher price than commercially known Colombian Emerald being Colombia the country that produces the most emeralds for the global market and has became the benchmark to distinguish the chromium element from vanadium by the use of the term “Colombian Emerald” or “Colombian type Emerald”.

One of the ‘precious four’ gems, natural Emeralds tend to have numerous inclusions and surface breaking fissures also known as d as jardin. Unlike diamonds (10x loupe magnification), emeralds are graded by eye hence an Emerald gemstone without visible inclusion is commonly considered flawless.

Generally considered parameters of the four C’s in Emeralds

Colour
When it comes to Emeralds, Colour is the single most important factor in determining the value of your gemstone. The most desirable Emerald colours are bluish green to pure green, with vivid colour saturation.

Clarity
Due to their formation conditions in nature and recovery methods, most emeralds contain surface reaching features. In natural Emerald expect to see inclusions known as an internal “jardin” or garden.

Cut
Due to the crystal shape emeralds are commonly cut as rectangular step cuts called emerald cuts.

Carat Weight
Due to its lower density, a one carat emerald may look larger in size than a one carat diamond.

Treatments
Most emeralds are “oiled treated” in a vacuum chamber under moderate heat, to open the pores of the stone and allow surface reaching fracture-filling agent to be absorbed.

The use of Cedar oil or other liquids, including synthetic oils is largely adopted practice accepted by the gem trade, thus “oil treated” emeralds are not necessarily worth less than un-treated emeralds. However, other treatments, for example the use of green tinted oil, are not acceptable in the trade. The levels of treatments are graded: none, minor, moderate and highly enhanced. In any case, no matter how accepted it may be, a reputable gem dealer should disclose if the Emeralds s/he is selling has been subjected to a treatment and the type of treatment so for the clients to make up their mind before purchasing the product.