Currently, Zambia ranks as the world’s most important source of emerald after Colombia. Emerald was discovered there in 1931, but commercial production did not begin until around 1967 at the Miku deposit. Peak production reached levels as high as 40 kilograms (88pounds) per month. Since then, digging has been initiated in one mine after another, such as the Kamakanga mine. Rough emeralds of over 100 carats with high transparency have been discovered, and efforts seem to be profitable. Interestingly, Zambian emerald rough is not the hexagonal cylinder shape seen in Colombian rough; instead, the crystals are irregular in shape.

More than half of Zambian rough is taken out of the country to be cut at polishing centers in India, Israel, and Germany. Because most Zambian and Brazilian emeralds are similar in color, polishing factories tend to handle material from both sources in the same way, with lower qualities often being sold mixed together.

Emerald is a variety of beryl, which also occurs in a wide range of colors other than green. Of the green beryls, those colored by chromium or vanadium are called emerald. Those colored green by iron are usually light green. The green of Zambian and Brazilian emeralds is generally caused by vanadium, and the difference between those and the chromium-colored Colombian emeralds is apparent in the beauty of their colors. Zambian material is bluer than the Colombian, and the color of some of the material lacks depth. However, stones of very attractive quality can be found in sizes of about 0.5 carats, and these are useful as the main stones in relatively affordable pieces of jewelry such as rings and pendants. Unfortunately, when comparing large stones of several carats to Colombian material, a considerable difference in attractiveness can be seen.

On the Mohs scale of hardness, which Iists diamond as 10, emerald is 7 1/2 to 8, harder than quartz at 7. However, due to an abundance of impurities and fractures, it is fragile. This is an important consideration when wearing emerald jewelry.