Gota de Aceite emeralds are a treasure to behold. They are equally as coveted as Golconda diamonds or Kashmir sapphires.
The Gota de Aceite [drop of oil] emerald, pronounced go-tah day ah-say-tay, is unique to Columbia. Its unusual structure causes the gem to have a velvety look to the naked eye. The phenomenon is sometimes referred to as the "butterfly effect", which is caused by calcite precipitation.
In order to qualify as a true Gota de Aceite emerald, it must have calcite precipitation. An emerald with simply a velvety look cannot qualify and thus should not be referred to as such. The butterfly effect can be seen under 10X or higher magnification. The look of the structure can be otherwise described as "roiling hot air" or "whiskey in water". It has a distinctively different look than the typical jardin' seen in most emeralds.
I have heard, Gota de Aceite emeralds sometimes slip by suppliers and get distributed in the marketplace. The novice often mistakes them for synthetic or even glass. Careful! Don’t act hasty; top color Gota de Aceite emeralds can be priced at $12,000 to 28,000 per carat! With so much at stake, a gemologist should assist in making an accurate identification.
So BOLOF (be on the lookout for) Gota de Aceite emeralds...you never know what may be lurking in the parcel right under your nose!
S.N.Nellis, PG RG
Last Update: 24 Nov 2008