Hi Again, a lot of people were asking about the color of Emeralds from different locations. The following was from an earlier blog post and covers a lot of that territory. I would like to add as a preface to what follows that many great stones have come from locations that are not well thought of in general. Good stones can come from many mines. This is true of Emerald but also of Tourmaline, Sapphire, Ruby and so forth. While generalizations are possible, specific stones can go against the generalizations and be truly wonderful or simply different. Hope you enjoy the additional discussion…..JR
Gems At Large® Blog May 2012 John and Laura Ramsey
Emerald— the May birthstone
by John Ramsey for Gems At Large®
What is emerald—emerald is a variety of the mineral beryl. Emerald is vibrant green variety of beryl usually colored by Chromium. In other colors beryl has other names. The blue color for beryl is aquamarine. Pink and peach beryl is Morganite. Yellow and golden beryl is heliodor. Red beryl is Bixbite and so far has only been found in Utah. Colorless beryl is called Goshenite. Chemically, beryl is a Beryllium-Aluminum Silicate. As mentioned emerald gets its green color from Chromium. There has been an addition to “emerald” of green gems colored by Vanadium but the classic emerald look comes from Chromium rich beryl. Interestingly, the red in ruby is caused by Chromium as well. Emerald is a type 3 gemstone according to GIA terminology and therefore can be expected to have eye visible inclusions.
Where emerald comes from—a fair question that people ask is “where do emeralds come from.” In a later paragraph we will show you a lot of the countries of the world where emeralds have been found from time to time. However, the real question people have has to do with current production in commercial quantities. Right now South America seems to be the production king of emeralds. Colombia is now known as the source for the most coveted emeralds. The color of the best Colombian emeralds and the fine transparency of the crystals from Colombia make them the quality king. What is it about the color of Colombian emeralds that people love? Well, first we have to talk about the color green. Green is a secondary color. Secondary colors are made from primary colors. In the case of green the primary colors are blue and yellow. Green can tip towards more blue or more yellow. Grass green, for instance, has more yellow in it when compared with the more bluish green of a fir tree. In the case of Colombian emeralds, the slightly bluish green tends to be very pure and not complicated by any over-tones of other colors—blue + yellow + no additional overtones = a very beautiful Colombian emerald green. That being said even within the production of Colombian emeralds there are color and quality differences. From Chivor the emeralds are slightly more bluish green and from Muzo the emeralds are slightly more yellowish green. But taken as a whole Colombian emerald is slightly more bluish than emerald from Russia. Prior to the ascendency of Colombian emeralds to the pinnacle of desirability Russian stones were considered the best. There may be some debate over this issue still. That debate would occur primarily in Europe.
For the first 15 years or so of my career in gems Brazil was known for producing emeralds in the state of Bahia—generally very poor quality emeralds. Then in the 1980’s there were two discoveries of emerald in Brazil: Santa Terezinha, Goais and Nova Era, Minas Gerais. Interestingly both of these discoveries produced emeralds of startling beauty. Some of the best stones of Nova Era rivaled gems from Colombia—maybe not the finest from Colombia—but Nova Era gems can be beautiful. Santa Terezinha emeralds have distinctly more yellow than Colombian stones but have a uniquely undeniable beauty.
But let’s not leave out African gems. Zambia has produced lots and lots of large attractive gems. Usually in my experience though the Zambian stones have a color that is marred by overtones of gray. But the Zambian stones can be large and relatively clean and truly lovely in the better quality.