In the world of Emerald, the most sought after and rare Emerald is the Gota de Aceite Emerald. It is pronounced “go-tah day ah-say-tay”. For collects, this type of Emerald is as rare as the Kashmir Sapphire or the Golconda Diamonds. If you are ever lucky enough to see one of these Emeralds, or own one, it should be cared for like no other stone.
In Spanish, Gota de Aceite means “drop of oil”. This name was given to the finest Emeralds by the Spanish conquistadors that showed a unique and very rare pattern. This pattern has a roiled appearance that looks like oil or honey. This is why the Spanish called these fine Emeralds “drop of oil Emerald”. This same effect has sometimes been referred to as the butterfly effect.
Emeralds that originate from Columbia are generally the only stones that can show Gota de Aceite. When it was originally discovered it was thought the the Emeralds grew around Calcite precipitations which caused the roiled effect in the Emerald that gave it the oil look. However with modern gemological tools it has been discovered that Calcite is probably not the cause of Gota de Aceite. Instead it looks like irregularities in the internal crystal structure of the gemstone are responsible for dispersing the light and causing the oiled look.
Gota de Aceite Emeralds to the naked eye look like the Emerald has an oily or velvety appearance. under 10x magnification with a loupe, the roiled effect becomes more evident. Some people refer to what they see as “Whiskey in water” or “Rolling hot air”.
In the market place, sometimes gem cutters and dealers might miss a stone that shows this effect. Some novice buyers might also discard these gems for synthetics or glass. Keep an eye out for any stones you think might have this apperance and take them to a gemologist to confirm. you never know what treasures might be right under your nose.
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