An Emerald, with a hardness of 7½ - 8 is one of the hardest minerals.
Emeralds are the most famous of the green gemstones, and also the most valuable. For this reason, and due to their composition, there are some problems with this particular group of gem stones.The deeper the green, the better the value. The stone shown at the top of this page is a middle green stone. We have a variety of other stones for sale at the shop.
Other, lesser known gem varieties, such as aquamarine and heliodor are also composed of Berl. Pure beryl is white. The green color of Emeralds is due to either chromium or vanadium impurities. Very pale emeralds are called "green beryl" instead of emerald. Green berl stones are sometimes heat-treated, to become aquamarine. Emeralds are notorious for their flaws and inclusions. Flawless stones are very uncommon, and so are of great value. However, the true collector prefers stones with inclusions and/or small flaws as they prove that the stone is natural and unaltered.