Emeralds & Other Green Gemstones

Most gemstones occur in a range of different colours. although each has a colour with which it is strongly associated, at least in most minds. If you were to ask people to name a green gemstone, emerald is the answer you would most frequently get, indeed many people would not be able to name another green gemstone. Other gemstones which are normally expected to be green include tourmaline, chrome tourmaline, tsavolite, peridot, chrome diopside, chrysoberyl, plasma, bloodstone, chrysoprase, prase, alexandrite, hiddenite, jade and sphene. Besides these which are usually green, there are a number of other gemstones which can occur in green, although they are best known in other colours, these include sapphire, spinel, agate and beryl.

Emeralds

Emeralds are the most famous and best known of the green gems. Emeralds occur in a range of different shades and hues of green, from very pale to deep, some with blue overtones. The most desired colour is a deep intense grass green, and this is therefore the most valuable and expensive colour. Inclusions in emeralds also affect ones perception of their colour. Most emeralds have many inclusions (imperfections), which can appear as cracks. These are most often black or colourless in appearance, but milky white inclusions are seen in some emeralds. Inclusions also affect the durability of emeralds.
A clear bright intense grass green emerald makes a very attractive gemstone, but prices for the best specimens are very high.
There are several problems with using emeralds in jewellery. Although they are quite hard, 7.5 to 8 on Moh's Scale, they are also slightly brittle, and their tendency to possess numerous inclusions makes them more liable to chipping and cracking. They do not tolerate heat well. In normal temperatures there are no problems, but the high temperatures involved when repairing using a jewellers' torch is likely to cause emeralds to shatter. Many emeralds are also treated by immersing in oil, clear or green coloured, to mask the numerous inclusions which reach the surface. This oil can evaporate in time, or be affected by detergents, so that the appearance of emeralds can deteriorate with time.
Diamonds are much harder, tougher and more durable than emeralds. Although most diamonds contain inclusions, they are usually much less noticeable than in emeralds, and have very little effect on the durability of diamonds. Like most coloured stones, green diamonds can be affected by high temperatures, but do not usually shatter, and any colour change is usually temporary.
Green diamonds, even enhanced ones, are much rarer than emeralds, and do not usually occur in such a wide range of variations in colour. If any diamonds exist which are in the preferred grass green of the best emeralds, we have not yet seen any, and they will be very rare indeed. If natural, they would also be extremely valuable.

Tourmalines

Tourmaline is usually considered as a green gemstone, although it does also occur in blue, pink, brown, and other colours. Usually it is a rather dark green, and not particularly bright or sparkly. A bright green variety known as chrome tourmaline can easily imitate the very best of emeralds, although it is also quite rare. The chrome in its name comes from the fact that its vivid green colouring is caused by the presence of chromium in its crystal structure. It is chromium which also gives emerald its distinctive and attractive green colour. Chromium also causes a similar colour in a number of other gemstones, including chrome diopside, and tsavolite, a bright green variety of garnet.

Green Sapphires

Sapphire is generally regarded as a blue stone, but can occur in any colour. Red sapphires are called rubies! Most green sapphires appear quite dark, and often have an oily appearance, lacking in brilliance. They are, like other sapphires, very hard and durable.

Green Diamonds Versus Other Green Gemstones

Because diamonds are much harder and more durable than any other gemstone, and because they also have more sparkle and brilliance than almost any other gemstone, they are more suitable for jewellery than other gems. These qualities apply to green diamonds just as for "white" diamonds. If you want a grass green gemstone, then you may have to settle for an emerald, you will be able to find a wider choice of colours. With green diamonds, the range of colours available to choose from is likely to be more restricted, but if you do find a green diamond in your favourite shade of green, then you should prefer it to any other green gemstone, in our opinion.