Gem Focus – March 2019

Posted on March 6, 2019 by Gemworld International

Aquamarine: The color of the sea when it’s calm…..

Aquamarine is considered to be the second most popular variety of beryl after emerald. While modern mineralogy states the varieties of beryl species with distinct definitions, ancients too were aware of the relation, although not clear how. Pliny lists a few “berylii” in his 37th book of Natural History with its resemblance to smaragdi (emerald) and six faced long crystal shape. He describes the color as “Of berylii, those are most esteemed of which are of a sea green, the color of the sea when it’s calm.”

Most gem quality aquamarine forms in pegmatites in considerably large sizes and high clarity. Eye clean material is common. Typical internal features are long, fine tubes and two-phase inclusions sometimes accompanied by solid inclusions such as mica, tourmaline and even hessonite garnet. The color description of aquamarine is very specific. As the name suggests, greenish blue to blue colors define aquamarine, sea-water as it has been at least for two millennia, generally in light to medium-light tones. It is nearly impossible to see darker, sapphire blues in aquamarine. The most valuable ones are saturated blue to slightly greenish blue in medium tones. Aquamarine is commonly cut in elongated forms such as rectangular emerald or rectangular brilliant cuts. These cuts best utilize the long hexagonal form in which the crystals grow in nature. This shape also allows cutters to display the maximum pleochroism.

Gem quality aquamarine occurrences are known in numerous locations. Brazil has been a major source since the beginning of the 19th century. Pakistan produces large amounts of aquamarine along with other beryl varieties. African countries, especially Mozambique, Nigeria, Zambia and Madagascar are also significant producers. China is known for small, commercial quality material in mass amounts for the world market.

Aquamarine is commonly heat treated to eliminate the greenish modifier as the market prefers the blue color more. As always, the gem professionals should be aware of clarity enhancements since any gem with surface reaching feathers and fissures is a good candidate for filling in today’s market.

Aquamarine has been one of the top selling colored stones in recent years. In fact, demand for aqua overshadowed emerald about two years ago but it has quickly changed this year. There is a fairly good supply of fine and extra fine quality material currently available in the market, especially in the smaller sizes. At the Tucson 2019 gem shows, prices were relatively consistent with the prices from the same period of the last two years. The exception is the upper fine category where prices have come down in response to slowing demand in the Chinese market.

(Click on download link below to view Aquamarine Historical Prices per carat.)

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