June 25, 2021
In the photo: aquamarine from Gem Lovers collection
Aquamarine is a gem known since ancient times. In order to consciously choose a specimen suitable for you, you need to understand the question of the definition and value of its characteristics. Which color is better, which shape of cut is preferable, where are gem quality crystals mined? In this article we talk about the nuances that affect and do not affect the quality, and, accordingly, the value:
Gem grade aquamarine is a clear stone, a type of beryl mineral. The name of this gem is translated as “sea water”. Aquamarine has the color of the sea, which is very different. The color palette includes cyan and blue tones. As an additional shade is green.
In nature aquamarines in most cases have a very light color, often with greenish tint. Sometimes it is so light that it may seem almost colorless, white, but a bluish tint should still be present. Blue stones are much less common in nature.
Stones with a rich blue color, are called “Maxixe”, by the name of the mine in Brazil, the color of such stones usually is not stable and often weakens in the light.
Aquamarines of bright and saturated blue color (deep blue) have the commercial name «Santa Maria».
It should be noted that the saturation of aquamarine depends on the weight. That is, specimens up to 1-2 carats will look almost colorless, even if the rough from which they were cut looked blue. With increasing weight the stone looks more saturated.
The color of aquamarine directly affects the price. The most expensive stones will have the most vivid blue color. For example, aquamarine of a medium blue tone (Medium blue) will be approximately 2-3 times cheaper than a sample of a saturated blue shade (Deep blue) with other things being equal, and 2-3 times more expensive than a very light bluish specimen (very light greenish blue). Keep in mind that greenish shades reduce the price.
It should be noted that aquamarine is often subjected to treatment. This may be heat treatment of yellow heliodor beryls to give a more valuable blue color, and irradiation of less saturated samples. At the same time, the treatment by most laboratories is not diagnosed and the fact of treatment does not affect the carat price. It can be considered that most of the blue aquamarines got their color using one of the treatment methods. However, there are also untreated. It is generally accepted that a light bluish-greenish color gives out a natural color, but this is not always the case.
Confidence in the seller, who keeps track of the history of his stones and has information on where a particular crystal was mined and whether it was treated, is important when buying. However, in most cases this data remains unknown.
Aquamarine crystals with clean, faceted areas can reach very large sizes. Therefore, high clarity in faceted aquamarine is the default. Perhaps, among all the precious and semiprecious stones, the phrase “pure water stone” is most applicable to aquamarine.
According to the GIA clarity rating system, aquamarines are of type I – usually eye clean. For our catalog we select mainly eye clean (VVS according to the GIA grade) and loupe.
In the presence of obvious defects in the form of noticeable inclusions and cracks, the price decreases significantly, by more than 50%, compared with stones of similar characteristics. Samples with inclusions are often used to make cabochons.
Two-phase gas-liquid inclusions and also mica crystals may occur. Etching channels are present in crystals rarely. They are thin, similar to silky villi, tubule voids, equally directed. If such a sample is correctly oriented during processing and cut in the cabochon shape – effect of a cat’s eye may reveal in a stone. This effect in aquamarines is not as bright as, for example, in chrysoberyl or tourmaline. But, nevertheless, it can have a collection value and be decorative, especially if the blue color is bright.
Aquamarines are extremely rarely faceted for small calibrated stones because small size stones up to 1 carat do not look blue, rather colorless. The color begins visible with a weight of stone exceeding 2-3 carats.
At a size of 5-10 carats, aquamarines are very attractive, the blue color of beryl is well defined, and this is probably the most successful size for an elegant ring or pendant that is comfortable to wear everyday. They look sophisticated, discreet, but at the same time expensive and noble. Products with similar stones are made individually and to order.
Instances weighing 15-20 carats are used to create unique jewelry to go out: sophisticated cocktail rings, diamond necklaces and luxurious pendants that perfectly fit the look for the red carpet.
As mentioned above, aquamarine crystals in nature are impressive in size and weight. For this reason sometimes on the market there are offers of items of collector value. These are really large samples of aquamarine, the size and weight of which limits their use in jewelry, and, as a rule, they adorn the interior and private collections.
Calibrated small light aquamarines are sold in a line of standardized sizes and shapes: round, oval, rectangles.
Larger samples are limited. Due to the elongated shape of the crystals, the most advantageous and popular form of aquamarine cutting is emerald cut (octagon). With this form, the yield when cutting pure crystals is greatest, in comparison with other forms.
Octagons, aschers and baguettes with regular, harmonious proportions in a step cut, are very beautiful.
There is another side: often cutters, in pursuit of profit, use almost the entire length of an aquamarine crystal, so that faceted baguettes (rectangles) become like long thin sticks. It is fair to say that some jewelry houses like to beat such a shape with an individual design, and very successfully, but in most cases, “sticks” are of little demand because of the non-standard shape. And secondly, the risk of damaging such a stone when fixing and the cut is high.
In addition to octagons and baguettes the forms of cushion, pear, and oval are popular. Pear-shaped aquamarines are used to create a romantic image of raindrops, for example, in earrings or pendants. A pear shape aquamarine in a ring will visually lengthen your fingers.
For aquamarine, as well as for other gemstones, the quality of cutting is important. Three main cutting criteria can be distinguished: proportions, symmetry and polishing of facets. Good cut quality implies that all three parameters are presented at a high level. Aquamarines are perfectly polished, so there should be no noticeable traces of the tool on the surface of the faces. The problem for aquamarines is the violated proportions in the ratio of the pavilion – the crown. The insufficient depth of the pavilion leads to the appearance of the “window” effect in a faceted stone. When viewed from the site, the surface on which the stone is located is visible. The excessive size of the pavilion part is inconvenient for fixing in the product, and, as a rule, is economically disadvantageous. You overpay for excess weight. There are exceptions when a low pavilion and a high play of light on the edges are combined in a faceted stone, they are considered winning for the buyer, since they look larger than they actually are. And are more profitable in value. For example, a stone of 8 carats looks like 10 carats, but stands for 8 carats. About such samples they say that they have a “big face.” Such aquamarines rarely appear on the market and are sold out rather quickly, as they are more likely a good chance for the buyer than a constant value.
There are aquamarine deposits in a number of countries. Among them are Brazil, Pakistan, Afghanistan, Ukraine, Myanmar (Burma.
Also, the sources of aquamarines are the countries of Africa: Mozambique, Madagascar, Namibia and Nigeria.
The main aquamarine deposit from Russia is the famous Sherlovaya Gora, which is located in Transbaikalia.
Aquamarine samples from Volyn’ (Ukraine) have a collection value. This deposit of beryls and topazes is considered to be developed today, however, sometimes single beryls appear in the market in crystals and cut for private collections. Crystals of transparent Volyn’ golden and greenish-yellow heliodors are very beautiful, they have a characteristic elongated shape and a natural surface with etching figures. After heat treatment, such beryls acquire an aquamarine blue color.
Vietnam also supplies natural aquamarines to the market. Their peculiarity is a rich bluish color, but the clarity is low, almost all the rough materials are cracked. Once upon a time, top blue aquamarines were mined in India, but today there is almost no production.
If we talk about aquamarine we can not ignore the deposits in Pakistan and Afghanistan. These countries are the birthplace of luxurious aquamarine crystals: of the correct crystallographic form, in perfectly preserved mother rock – a real miracle, the dream of a collector of minerals! However, aquamarines of saturated blue colors are not found in these deposits, all stones are quite light.
Most stones in the modern international market are still of brazilian origin, although african aquamarines from Mozambique and Madagascar are gaining popularity.
Since aquamarine is very popular, imitations and fakes are also common. It is imitated by glasses (also called pastes), ceramic, synthetic materials, for example, synthetic spinel, YAG, GGG.
In order to distinguish aquamarine from imitations and fakes, knowledge of gemologists and at least a minimal set of gemological equipment are needed: loupe, refractometer, polariscope.
Glass and glass ceramic gives out the presence of bubbles in the stone when viewed in a 10x magnifier. Old glasses can have a lot of scratches on the surface.
Also, glass can be distinguished by a polariscope: in polarized light, aquamarine will show a picture of anisotropic substance (when turned 360 degrees, the stone will darken and brighten 4 times), and glass will show a picture of isotropic substance, or anomalous anisotropy (dark lines are beams).
You can also check hardness. Aquamarine will not be scratched by a steel blade, and scratches will remain on the glass. But we do not recommend this method for faceted samples. You can distinguish natural aquamarine from synthetic spinel and other synthetics using a refractometer by measuring the refractive index of a polished facet. For aquamarine, the refractive index will show values in the range of 1.57-1.59, a characteristic birefringence of 0.005. Synthetic spinel and YAG have a much higher value.
On the photo: MGL laboratory certificate for natural aquamarine
Aquamarine can be similar to other stones of blue colors: blue zircon, topaz, rarely – light tourmaline, sapphire, diamond.
These stones can also be visually distinguished from aquamarine. Zircon and diamond give a high dispersion. Topaz has a colder and more saturated blue tint.
In any case if you have any doubts about the natural origin, we recommend that you contact a reputable laboratory where you can order a certificate. Please note that the laboratory most likely will not determine if the stone was treated or not, but will establish the natural origin and indicate the main characteristics of aquamarine.
On the photo: certificate (report) for aquamarine from AGL laboratory
How much is a natural aquamarine? Consider the approximate prices per 1 carat of stone of certain characteristics: clarity – eye clean, acceptable Asian cut of good quality, medium-saturated blue, not warmed, heat treatment is also acceptable, depending on the weight range of the specimen.
With a further increase in weight over 15 carats, the price does not increase.
You may think that such prices are too high for aquamarine, but note that the cost is for stones without an additional greenish tint, that is, pure blue. The largest part of aquamarines on the market is light greenish blue stones, they are approximately 1.5-2 times cheaper than blue stones (medium blue).
The presence of clarity defects in the specimen (cracks, inclusions) reduces the cost by up to 50-80%.
European-level cut aquamarines are at least 10-15% more expensive than the indicated price. If the quality of the cut is low (obvious asymmetry, imbalance, a noticeable “window”, a pavilion too deep, a disproportionately high crown), stones are usually sold at a discount of up to 20%.
You can choose and buy aquamarine in our catalog.
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