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Brillant round cut

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Opale Naturale Composito

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Qualità e valutazione dei Black Opals

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Varieties of Natural Opal

The variety of natural opal is determined by the two characteristics of body tone and transparency.Body ToneThe body tone of an opal is different to the play-of-colour displayed in precious opal. There are three varieties of natural opal based on body tone.Black Opal - N1, N2, N3 o N4Dark Opal - N5 o N6Light Opal . N7, N8, N9 Body tone refers to the relative darkness or lightness of the opal when ignoring the play-of-colour.Opal with a distinct coloured body (such as ye...

Natural Opal

Natural opal is opal which has not been treated or enhanced in any way other than by cutting and polishing. There are three types of natural opal, with varieties described by the two characteristics of body tone and transparency.

Classification

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Care

Proper care of pearls is not difficult if you remember that they are organic and produced by a living thing. Pearls are soft and delicate, but when cared for with common sense, they will maintain their lustre for centuries. The pearls should not come in contact with cosmetics, hairspray, perfume, chlorinated water, or other harsh chemicals. To keep them clean, let them be the last item put on when dressing, and the first item taken off at the end of an evening. The best way to maintain their lus...

Mabe Pearls

A mabe pearl is an hemispherical shaped pearl which, grown against the inside of the oyster's shell, rather than within its tissue. Mabes occasionally appear in nature. Cultured mabes are grown intentionally, by using an hemispheric nucleus - rather than a round one - and by implanting it against the oyster's shell, rather than within its tissue. The pearl then develops in an hemispheric form, with a flat back. While in the oyster a mabe pearl is actually considered a blister pearl not a mabe pe...

keshi Pearls

Keshi pearls are formed when the oyster rejects and spits out the implanted nucleus before the culturing process is complete, or the implanted mantle tissue fractures and forms separate pearl sacs without nuclei. It Keshi may form in either saltwater or freshwater pearls. They are generally small in size and, because there was no nucleus to guide the ultimate shaping of the pearl, their shapes vary widely. Keshi come in a wide variety of colors, and tend to have high luster and even rare orient...

Tahitian Cultured Pearls

The natural black color of the Tahitian pearl comes from the black-lipped variety of the pinctada maxima oyster. These oysters are farmed on the volcanic atolls of Tahiti, where the mixture of nutrient-rich ocean water mixes with warm lagoons creating an ideal environment for them--and the only place where Tahitian pearls can be found. Like the South Sea pearl oyster, the black lipped pinctada maxima is sensitive to the cultivation process, making the Tahitian pearl rare and expensive. Though th...

South Sea Cultured Pearls

South Sea pearls are primarily cultured in the northern waters of Australia, the Philippines, and Indonesia. They are either white or black with silver overtones. Because of their size and high lustre, and the sensitivity of the oyster to culturing, they are quite valuable and rare. They average from 11-13mm, but can even be found as large as 20mm. The oyster that produces these pearls is considerably larger than those that produce Akoya pearls, and is extremely sensitive to the cultivation proc...

Akoya Cultured Pearls

Akoya pearls are produced in several varieties of saltwater mollusks in Japan and China. They were the first to be cultured in the early 1920s and are the most popular pearls used in strands and earrings. They produce the most consistently round pearls with high lustre and very slight imperfections. Their colors range from cream and white to white-rosé. Initially, they look similar to round Freshwater pearls, but compared side-by-side, the difference in lustre and color is obvious.

Surface Markings

Often when an oyster creates a pearl, the nacre does not develop smoothly. The surface of a pearl is judged by how many marks are visible in the nacre. These imperfections can be small and unnoticeable or quite large and distinct. Like diamonds, pearls are rarely flawless. However, high lustre or the way pearls are strung and set can help conceal surface markings.

Size

An oyster’s particular type and size has a direct effect on how large the pearl it produces will be, and pearls do come in a wide range of sizes. Round pearls are measured according to their diameter, while baroque pearls are measured by their length and width. A pearl’s size does not necessarily affect its quality, but it does affect its price. Large, round pearls are rare and their lustre is usually high--this beautiful combination of traits is often reflected in the cost of such pearls. A...

Shape

While pearls come in many different shapes, the rarest and highest-quality are round. Akoya, Tahitian, and South Sea oysters tend to produce the roundest pearls, while those of Freshwater mollusks can be oval to slightly off-round. When considering a pearl purchase, whether it be a necklace, bracelet, or earrings, look for consistency in the shapes of the pearls. Many of the less symmetrical shapes are used in stylish jewelry which can be quite beautiful: the drop pearl’s shape lends well to e...

Lustre

The appealing, deep shine of a pearl is often what defines its beauty. This shine is produced by multiple layers of semi-opaque calcium carbonate crystals, called nacre. The nacre reflects light on the surface of the pearl, producing brilliance and sheen. Lustre is an integral feature in determining the quality of a pearl. Large pearls have a thicker nacre and, therefore, a higher lustre. When comparing a small Freshwater pearl to a large South Sea pearl, the difference is clearly visible to the...

Colour

Mollusks produce pearls in a variety of colors, accommodating most personal preferences and budgets. The general color of a pearl is also known as the body color. Pearls typically range from white, cream, and yellow to pink, silver, or black. An overtone of secondary color is sometimes seen. For instance, a pearl may appear to be white, but upon closer inspection a rosy hue is detected. The body color would then be termed white-rosé. Color variation does not affect the quality of the pearl, tho...

Cultivation

Pearls are produced naturally in the body of salt and freshwater mollusks, such as oysters and mussels. When these animals sense an irritant, such as a grain of sand, they produce a soft coating of calcium carbonate substance around it: nacre. The result is a pearl. Because perfectly round, naturally produced pearls are so rare, a process known as cultivation was developed by Kokichi Mikimoto in the early 1900s. A small bead of polished shell, the nucleus, is used as an irritant and delicately i...

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