Emerald is the green variety of beryl. Only red emeralds are rarer. An emerald ring is hard, a 7 ½ to 8 out of 10 on the Mohs hardness scale, but is very brittle. It is under more stress because of the possibility of fractures. It is for that reason that emerald gemstone rings are not good everyday rings to wear. It would be better to have emerald earrings or necklace for everyday wear. An emerald eternity band would also be better worn on an occasional basis as a quick whack of the wrist can chip or crack your emerald. The best quality emerald is the color of “young green grass” with a faint hint of blue. Columbia is known to produce the best emeralds, but other sources include Zambia, Brazil, Pakistan, Afghanistan, Russia and India. Even North Carolina in the United States is known for its gem quality emeralds. Emeralds without flaws are extremely rare which is why it is suspect to see flawless emeralds. Flaws are considered fingerprints of an emerald and those fingerprints mark the emerald as your own. Your natural emerald ring is a very popular jewelry item. That is why imitation emeralds were created to keep up with demand at a less expensive price. Synthetic emeralds, however, are being produced with the same hardness and flaws of a natural emerald. Although not inexpensive, it is lower in price than a natural emerald of the same quality. A natural procedure for an emerald is oiling. It fills in cracks and hides flaws and is actually good for the stone as it is fragile, a luxury stone. Today, emeralds are oiled by way of vacuum heat technology and is a common accepted practice. An ultrasonic should never be used to clean an emerald as it can remove the oil which lightens the color of the gemstone. It is good to know that emeralds can be re-oiled.