Facts you need to know about aquamarine

Aquamarine General Information

In the beryl species, aquamarine is second only to emerald in popularity. Fine aquamarines are combined with diamonds and set in platinum in this jewelry set.

The name “aquamarine” is derived from two Latin words: aqua, meaning “water” and marina, meaning “of the sea.”

In the commercial market, aquamarine competes with treated blue topaz for attention, but fine aquamarine sells for much more than treated blue topaz of equivalent quality. In early 2012, wholesale prices for a good quality 3-carat stone of African origin ranged from $65 to $120 per carat, depending on the degree of color saturation.

Aquamarine’s hardness and transparency make it popular with designers, artists, and carvers. Gem carvers use aquamarine for fancy cuts and ornamental objects.

The color range of aquamarine is very narrow: it can be blue, very slightly greenish blue, greenish blue, very strong greenish blue or greenish blue.

Despite Sapphire The most popular blue gemstone, aquamarine is one of many other blue stones that have sizeable markets of their own. However, even in its darkest hues, aquamarine rarely matches the blue of sapphire.

Like most beryls, well-formed aquamarine crystals are usually six-sided columns with flat faces at their ends.

Cut:

The cutters align the table facet parallel to the length of the crystal. The gem is pleochroic and shows a strong, almost colorless blue in different directions of the crystal. Fortunately, the pleochroic blue color matches the cutting orientation that retains the most weight. Cutters often model aquamarines as emerald cuts or as round or oval brilliants. The rough is quite abundant, so there are usually well-cut stones. Aquamarine crystals can range from very small to very large, up to 100 pounds. (45 kg) in some cases. Large stones are readily available, but very large stones are difficult to use in jewelry, so there is less demand for them. As a result, prices per carat tend to decrease for sizes above 25 cts.

Modern aquamarines often have to be quite large, usually over 5 carats, to display deep, dark color. Although small gems are rarely saturated enough to be attractive, stones from some mines in Africa (Nigeria, Madagascar, and Mozambique, for example) are known for their intense color at sizes below 5 cts. For this reason, smaller stones of the top color can sell for more per carat than larger stones of the same color.

Clarity

Most faceted aquamarines are clean on the eyes. Some crystals may contain liquid inclusions, but clarity characteristics are few or absent in most finished gems.

Imitations and synthetics of aquamarine

Russian growers produce hydrothermal synthetic aquamarine, but it is not widely available. The most common aquamarine imitations are treated blue topaz, pale blue glass, cobalt colored synthetic blue spinel.

Separating natural aquamarine from all other imitations can be quite easy. Standard gemological tests such as the refractive index and the Chelsea filter easily distinguish aquamarine from its imitators.

Aquamarine Sources and Market Today

Brazil

Brazil has been the world’s foremost source of gem-quality aquamarine since 1811, when a miner found a large aquamarine crystal in a riverbed near Teófilo Otoni. He weighed about 15 pounds. (7 kg), and was the first large aquamarine crystal ever recorded. Millions of carats of fine aquamarine have been found in the thousands of mines in the region. The largest recorded aquamarine crystal was found in 1910, in Minas Gerais, Brazil. 244 lbs. (110 kg) 19 in. (48 cm) long and 15 in. (38cm) diameter

Although the fine blue-green glass was water-worn, most of it was gem-quality and so transparent that people could read printed pages across the glass.

When German immigrants settled in Brazil around 1850, they discovered that they could dig almost anywhere, with almost any kind of equipment, and find aquamarine crystals. Someone sent samples to Idar-Oberstein, Germany, then, as now, a major cutting center, for examination. That was the beginning of a close gemstone mining and trading relationship between Brazilian miners and German cutters.

Most of the aquamarine mines are located in the northeast of Minas Gerais. Although some darker crystals come directly from pegmatite, alluvial deposits produce most of the material. Historically, aquamarine and other gems have been found in riverbeds or dug out of the ground by independent miners called garimpeiros. Because the new laws make it difficult for the garimpeiros to operate, the recovery method has changed to mechanized open pit mining.

There are no precise figures for the production of Brazilian gems because official records are not kept. Commercial sources estimate, however, that less than 5 percent of the yield from Minas Gerais consists of premium quality dark blue stones.

Pakistan

Pakistan is another major producer of aquamarine. Pegmatites produce light green and blue crystals, some as large as 12 inches. (30 cm) long by 5 in. (12cm) wide. Miners also find ink-blue crystals.

Porcelain

China recently became the world’s leading producer of commercial grade small aquamarine. Most stones are around 6x4mm, with commercial grade sizes rarely exceeding 10x8mm, or around 2 carats. Crude mining techniques damage many crystals, and the yield of gem-quality crystals is only 10 to 15 percent. Some members of the trade say that if Chinese miners were more careful, they could produce larger stones with a deeper color.

Chinese aquamarine has replaced the Brazilian material in most of the mass-marketed jewelry available through home shopping networks and other high-volume outlets.

The introduction of treated blue topaz in the 1980s had a negative effect on the aquamarine market in the United States, but not elsewhere. Consumers in Japan and Europe preferred aquamarine and were willing to pay high prices for premium gems.

In the late 1990s, Japan was the best market for high-quality aquamarine. Medium to high quality stones also sold well in Germany and Italy, and almost all grades were marketable in the US.

Nigeria

Nigeria has been known to be a source of aquamarine producing large, clean material since the early 1990s. Generally speaking, most characteristic colors of Nigerian aquamarine are light blue-green to blue and fairly uniform in color. . This makes them favorable among many television shopping networks that produce silver jewelry for the mass market.

mozambique and madagascar

The Madagascar and Mozambique deposits are the most recent discovery of high-quality, dark-colored aquamarine to have been unearthed. Material in Mozambique may possess a particularly rich blue hue cut aquamarine which is a true treasure of this area.

From Mozambique “Santa Maria color” Aqua has a very fine natural blue. Furthermore, it has been distinguished from aquamarine from other localities by the ability to maintain a strong color even in small stones. Pocket-rich pegmatites containing beryl gems are prevalent and spread across the entire African continent. It seems to me that for a short time, we will expect to see more aquamarine production from many parts of Africa.

Less important sources are Australia, Kenya, USA and Zambia.

Aquamarine Treatments

Virtually all of the blue color in aquamarine is derived from heat treating bluish-green, greenish-yellow, or even brownish-yellow gems. The heating control process can remove the yellow color component and leaves a purer blue tone in the stone.

Heat treatment:

It is standard practice to cut the rough stones and then heat the shaped stones. Because aquamarines are largely free of liquid inclusions, they respond well to heat treatment. Depending on the source mine and the clarity of the stones, treaters heat the aquamarine between 482ºF and 1292ºF (250ºC and 700ºC) for varying periods of time. Treaters heat stones with significant inclusions for longer periods, at lower temperatures. In most cases, aquamarine heat treatment cannot be detected and the treated color appears to be permanent.

Some dealers, however, leave blue-green aquamarine untreated and use its uniqueness to promote it. Its untreated color sets it apart from its competitor, the treated blue topaz. Some dealers see the saturated blue topaz market as a sign of good times ahead for aquamarine. And because of today’s widespread concern about treatments, untreated gemstones like naturally colored aquamarine are attracting more consumers than ever.