Why Does Gold Discolor Fingers?
The most common reason is metallic abrasion, caused by makeup on skin or clothing. Cosmetics often contain compounds harder than the jewelry itself, which wear or rub off very tiny particles. Very finely divided metal always appears black rather than metallic, so it looks like a jet-black dust. When this dust comes into contact with absorbent surfaces such as skin or clothing, it sticks, forming a black smudge.
To prevent this, your customers should try switching cosmetics. If this is not possible, recommend that they remove rings and other jewelry while applying them, and clean skin areas in contact with jewelry with soap and water.
Another cause is actual corrosion of the metals. Gold itself does not corrode, but its primary alloys of silver or copper will do so (forming very dark chemical compounds) under moist or wet conditions.
When your customer perspires, fats and fatty acids released can cause corrosion of 14-karat gold, especially when exposed to warmth and air. This problem can be worse in seacoast and semitropical areas, where chlorides combine with perspiration to form a corrosive element that discolors skin. Smog fumes gradually attack jewelry and are evident as a tarnish that rubs off on the skin.
We suggest that our customer remove jewelry often and use an absorbent powder, free of abrasives, on skin that comes into contact with jewelry.
Even the design of jewelry can be an influence. Wide shanks have more surface area to contact abrasives or corrosives. Concave surfaces inside a shank form collection points that trap moisture and contaminants, also causing a type of dermatitis.
Customers should remove all rings before using soaps, cleaning compounds or detergents, and clean their rings frequently. As well as solving the problem, they'll be amazed at how much better your rings look!
In addition to these corrective actions, recommend that customers switch to 18-karat gold or platinum. The lower alloy content of 18-karat gold (25%, versus almost 42%) significantly reduces the problem, and the use of platinum should eliminate it completely.
How do I pick my pearls?
Selecting PearlsPearls are classified by origin, and then graded by size, shape, nacre thickness, color, luster, and surface clarity. These qualities are not considered to be of equal importance when arriving at the final grade. When selecting pearls, be familiar with the "Five-Virtues" of pearls to assist you in selecting your ideal pearl. However, the most important thing to remember when selecting a pearl is that "beauty is in the eye of the beholder."
For cultured pearl experts, luster is the single most important indicator in evaluating pearl quality. Luster is what separates the superior from the inferior and the extraordinary from the ordinary. Throughout history, this unique attribute has separated pearls from all other gems.
Luster describes the beauty you see as light travels through the nacre of the pearl. Luster derives from the pearl’s countless layers of pearl nacre, the natural pearly substance that forms the body of the pearl itself. It is the nacre of the pearl that causes light to refract from the depths of the nacreous layers through minute prisms, giving each pearl its unique lustrous appearance.
The luster of these pearls is natural and untreated, and as such their beauty will not diminish over time if cared for properly.
Pearls may have surface characteristics, which may or may not detract from the pearl’s beauty depending on the quality, depth, or visibility of the blemishes. Pearl nacre is a beautiful matrix of calcium carbonate crystal laid on tile-like formation by the oyster. The appearance of the nacre is determined by several factors including whether the calcium crystals are “flat” or “prismatic,” the perfection with which the tiles are laid, and the fineness and number of tiles. When the tiles are laid in a perfectly uniform pattern the nacre will appear identical over the entire pearl surface, thus creating the “flawless” pearl.
Nature is not normally flawless, however, and some tiles may be imperfectly laid. This results in surface blemishes and imperfections beneath the nacre’s surface. The effect on the pearl’s beauty depends on the degree of visibility of these imperfections. This is described as the pearl’s complexion.
Surface complexion quality refers specifically to the abundance or absence of physical blemishes or marks. When evaluating complexion (the trade uses terms such as blemish, spotting and cleanliness), remember that cultured pearls are grown by live oysters in a natural environment. As such, there are many uncontrollable forces that affect the surface.
Cultured pearls are measured by their diameter in millimeters. They can be smaller than one millimeter in the case of tiny seed pearls, or as large as twenty millimeters for a mature South Sea pearl. The larger the pearl, other factors being equal, the more valuable it will be.
What kind of Pearls are there to choose from?
South Sea Pearls
The allure of South Sea pearls is legendary. From the 1800’s, Australia was the primary source of the world's largest, most voluptuous and most valuable natural pearl, the South Sea pearl. The Australians knew their pearls would be highly sought after, and they successfully pioneered the South Sea cultured pearl industry by coaxing the sensitive oyster into yielding a cultured pearl.
South Sea cultured pearls range from 10.0 to 15.0 mm, but larger examples can reach up to 20.0 mm. Only cultured pearls from the Pinctada Maxima possess the beautiful transparency and color overtones with rainbow hues ranging from white pink to silver pink to dark gold.
Originally exclusive to Australia, South Sea cultured pearls are now farmed in Indonesia, Burma, and the Philippines. However, the characteristics and quality of pearls from these regions can vary greatly. Australian oysters and ocean conditions are generally credited with producing the largest and finest quality pearls. Australian pearls can throw fancy colors including red gold which is extremely rare and highly regarded. Indonesia and Burma produce mainly white to yellow and also gold, while the Philippines produce mainly yellow and gold.
The Pinctada Maxima oyster is rare and will not survive outside the small area of its natural environment, making it extremely difficult to cultivate. Highly labor intensive, farms are by necessity situated in remote locations. To protect the wild natural stocks of oysters in Australia, the government strictly enforces production quotas. Not every Pinctada Maxima will produce a pearl and each oyster can grow only one pearl at a time. Good quality, 10.0 to 15.0 mm pearls usually take two years to grow. Larger pearls are generally found after the fourth or sixth year of the farming cycle.
What sets South Sea cultured pearls apart is the unique beauty of their nacre. As with all natural South Sea pearls, it is the quality and thickness of nacre that gives the pearls incredible luster that will last for generations. In high quality pearls, nacre thickness tends to be at least 3.0 mm and in many cases will reach over 6.0 mm.
Quality and rarity are the defining factors in determining the value of the finest South Sea cultured pearls. Pearl luster and color are the primary influences on a pearl's quality. These attributed are determined by the pearl nacre so, the finer the nacre the better luster and color and the valuable the pearl. All of Stuller’s pearl strands are of exceptional luster and arrive in your store with a guarantee that the luster and color are natural, not enhanced by artificial means.
The meticulous matching required to create an extraordinary strand can take up to a decade. Constructing such a precious piece is a process with no room for compromise. Stuller offers uniform and graduated strands to maximize customer choice.
Tahitian pearls, often called “Black Pearls,” are found in the warm, turquoise-colored lagoons of French Polynesia on the South Seas. Their opalescent black hue, shimmering with peacock green, grey and purple overtones, makes a sensual, smoldering statement in jewelry designs for both men and women. Natural coloration yields shades of grey to black. Consistency of color tone is highly desirable with peacock tones demanding the highest prices.
The Pinctada margaritifera, or “black lipped” oyster is a giant tropical mollusk that can live for 30 years in the wild, can weigh up to 100 pounds and can grow to reach over 12 inches in diameter. In the 19th century, free-diving Polynesians braved sharks, depths of up to 130 feet, and the physiological challenges of deep water diving to harvest these valuable mollusks. Although only one in 15,000 oysters produced a natural pearl, the inner shell was so popular with the European button industry that the resource was eventually devastated.
Today, a complex cultivation process has resurrected the pearl industry in French Polynesia. The government has strict regulations to assure pearl quality. Pearls are now farmed throughout French Polynesia, Northern Australia, and the Marshall, Cook, and Solomon Islands.
Tahitian pearls are usually found in sizes from 8.0 mm to 13.0 mm; sizes up to and exceeding 20.0 mm are sometimes discovered, but are quite rare and highly prized. Tahitian pearls, like their South Sea cousins, come in a variety of shapes. As with South Sea pearls, nacre quality is the defining measure of quality and value.
Single pearls set in cuff links, on a cord, or as a tie stud make a great gift for men who seek a sophisticated look with natural appeal. For women of all ages, few gems offer greater drama than strands of Tahitian pearls, dynamic for daytime or evening wear. Used individually or in combination with white or golden pearls, black pearls create superbly fashionable jewelry that with proper care, will last for generations.
Fresh Water Pearls
Although originally produced in Japan, 90% of the world’s freshwater pearls now come from China. Unlike other pearls on the market, freshwater pearls typically do not come from an oyster at all. Most such pearls are farmed in varieties of freshwater mussels, including Hyriopsis and Cristaria. Each shell can produce up to 100 pearls simultaneously.
Most freshwater cultured pearls are nucleated with pieces of mantle tissue – rather than a round nucleus, which is placed directly into a mussel’s mantle to initiate nacre production. Mantle tissue is shell material that is recycled into the formation of new pearls. As with Akoya pearls, freshwater pearls are not marketable for jewelry in their natural state, and require clinical enhancements such as bleaching, coloring, and polishing.
Traditionally, most cultured freshwater pearls grow in irregular shapes from near round to oval, between 2.0 to 5.0 mm. New farming and pearl-enhancement technology has enabled the production of more round pearls and a whole new array of colors, now producing freshwater pearls in sizes up to 9.5 mm. Supply is plentiful and quality is highly variable, consequently the price of freshwater pearls varies and is generally lower than other cultured pearls.
Akoya pearls are the classic and best-known variety of all cultured pearls. The roundness of the pearl and the depth and consistency of luster have positioned this pearl as the preferred choice in making a timeless statement of good taste in jewelry selection. When thinking of a simple pearl necklace as a bridal choice, or to accent that “little black dress,” the Akoya pearl sets the standard as the premier choice.
Water temperature and mineral content will influence the quality of pearl production. Cool to cold water produces best results. While Akoya producing mollusks are found in ocean waters bordering certain areas of the eastern coasts of North and South America, the east coast of Africa, the Mediterranean and throughout the Indo-Pacific region, the vast majority of the Akoya producing mollusks are found off shore Japan.
This natural phenomenon, made famous by Kokichi Mikimoto who helped perfect modern-day pearl culturing techniques together with the evolution of the cultured pearl production process since the early 1900’s, has formed the basis of a multi-billion dollar pearl industry. Successful pearling is the result of thoughtful planning, patient tending and nurturing of the producing mollusks and an enormous investment in time, money, science, and people.
The Akoya producing mollusk (the Pinctada fucata martensii) produces pearls between 2.0 and 9.0 mm in size. Each shell produces four to five pearls at a time with a nacre thickness of approximately 1/10 to 2/10 of a millimeter. The growing time for most Akoya pearls is from 6 to 18 months. A longer cultivation timeline can produce a higher valued pearl. The overtones of the average Akoya pearl range from pale cream to pinkish white, champagne, and silvery grey. These overtone hues, when properly matched to the completion of their owner, are what make pearl jewelry a unique statement of perfection and grace.
Once the pearls are recovered, the lengthy and highly skilled process of hand sorting, grading and valuing the pearls for market sale begins. Appraisal of the pearl considers natural luster, surface smoothness, size and degree of roughness. White color is not an absolute in determining the value of Akoya pearls, whiteness with pink undertones is considered to be highly valued.
How can I test a pearl to see if they are real?
Believe it or not, you can put a pearl to your teeth and rub it along your tooth. You will feel a grit like sand texture if it is real! Imitation pearls are usually smooth on the your teeth.