May's Birthstone: Emerald

The emerald is one of the “Big Four” gemstones, known as the precious stones. Emeralds are made of a mineral called Beryl, with trace amounts of the elements chromium or vanadium which give this gemstone its distinct green color.

When assessing Emeralds, we use the same 4C’s as we do for diamonds (Color, Carat, Clarity & Cut). However, the importance of each specification & the amount it contributes to the value of a stone differs between the two gems. Let us take a look at each component, in order of importance to emeralds:

Color:

An emerald’s rich green color is arguably the most important quality factor that characterizes it. The color grade is further broken down into saturation, hue, and tone. Together, these three categories are the major keys to choosing the right Emerald. Stones with darker tone, bluish greenish hue and vivid saturation generally command the highest price tags in the market.

There is no clear consensus when it comes to qualifying stones as Emeralds by their color. For example, beryl without chromium or vanadium inclusions would be colorless (gohenite) and that will not qualify to be called emerald. In addition, beryl may be found with traces of iron tinting the stone to a bluish green (aquamarine) or yellowish green (helidor) depending on the oxidization state. Gem experts don’t always agree on the degree of green color that makes a stone an emerald or just a green beryl (which is a cheaper stone with usually much lighter green color).

Clarity:

Unlike diamonds, most Emerald stones are expected to show visible inclusions. These visible inclusions are a result of them belonging to the Beryl mineral family which almost always include bits of liquid, gas, and salts when they are formed naturally. As a result of their highly included nature, Emeralds are usually treated by producers and vendors in order to improve their appearance. Most cut emeralds are treated with oils, waxes, polymers, or other materials that make natural inclusions less obvious and emphasize the green color of the stone.

Cut:

In their natural state, emeralds are usually hexagonal crystals (flat topped columns). As a result, the ideal cut for emeralds results in symmetrical, uniform facets that allow as much color and brilliance to shine through. Cuts too deep or too shallow restrict light from escaping, causing the emerald to lose its vivid color and appear dark. In order to achieve the most desirable combination of symmetry, light reflection, and rough preservation, most cutters choose to cut Emeralds into the square or rectangular emerald-shaped cut. Oval, pear, cabochon and round shapes are not seen as much because they lead to a greater loss of rough and hence a lower sale value.

Carat weight:

Emeralds have lower density than diamonds. Consequently, a 1 carat emerald will generally be larger in size than a 1 carat diamond. Just like diamonds, a 4 carat emerald will cost much more than a 1 carat emerald all other factors being equal. However, carat weight is not as important as color when it comes to emeralds. Therefore, buying a smaller emerald with excellent color can cost you more than buying a bigger emerald with poor color.

Since most emeralds are heavily included, about 80-95% of the rough is usually cut away to produce the beautiful gemstone. This would give a smaller yield and hence increase the price tag. Due to emerald being among the rarest of all gemstones, the value of emeralds can compete to be more expensive than diamonds as their color and clarity goes up in scale to give the gem a greater quality. The rarity and craftsmanship needed to produce a perfect colored gem gave the emerald gem a very distinguished status and that is why it is seen to be a part of the jewels adorned by various royal families thought history.

The 4C’s will help direct you to choosing emeralds better. Let us end our post this week with some fun and interesting facts regarding this rare and beautiful gemstone. Inclusions appear in almost 90% of all emeralds, dealers usually call them Jardin (garden in French) since they usually appear tree-like or floral inside the stone. Even though inclusions are natural to find, try to choose emeralds with deeper or under-the-surface inclusions so you can avoid fractures when being set or worn (especially since they are stones that can chip easily). Emerald’s inclusions effect not only the stones clarity but also its structural integrity. Treatments of emerald stones might improve appearance of the stone but, it will not be able to improve durability of the gem causing it to discolor or deteriorate overtime. Emerald gems are better used for jewellery pieces that are made for special occasions rather than daily use. It is also preferred to use it in earrings, necklaces rather than rings and bracelets. And also, it is preferred to use it on more fixed settings rather than looser jewellery settings. That is due to the gem holding up more durability when less impact and abrasion is applied to it.

And finally, since Emeralds have been connected throughout history with love, grace and, beauty. You should know they are known to be the ideal gifts for special occasions and especially for the twentieth and thirty fifth wedding anniversaries.