A wedding ring or wedding band is a metal ring indicating the wearer is married. Depending on the local culture, it is on the base of the right or the left ring finger. The custom of wearing such a ring has spread widely beyond its origin in Europe. Originally worn by wives only, wedding rings became customary for both husbands and wives during the 20th century. According to some customs, the wedding ring forms the last in a series of gifts, which also may include the engagement ring, traditionally given as a betrothal present. This tradition was already in use in Ancient Rome and is possibly much older. Historically, the wedding ring connected to the exchange of valuables at the moment of the wedding rather than a symbol of eternal love and devotion. It is from the times when marriage was a contract between families. After marriage, the ring worn on the hand placed on during the ceremony. By wearing rings on the fourth finger, a married couple symbolically declares their eternal love for each other. This has now become a matter of tradition and etiquette. One interpretation states that the woman wears the wedding ring below the engagement ring, thus making it closer to the heart. Another practice holds that the woman should wear the wedding ring above the engagement ring, thus sealing the atmosphere of the engagement into the marriage. Still others prefer that the wedding ring worn alone. Further, modern ring sets in the United States are often as a three-piece set, including the man's wedding band, the woman's engagement ring, and a slender band that mounted to the engagement ring before the wedding, converting it into a single, permanent wedding ring. Some cultures exchange additional rings: In some parts of India, Hindus may use a toe ring worn instead of a ring on a finger, although this is only for women, and increasingly worn along with a finger ring. In Romania, spouses celebrate their silver wedding anniversary by exchanging silver wedding rings, which worn on the fourth finger of the left hand along with the original wedding ring. The wedding ring removed for comfort or safety. It is common for those who have professions that forbid the wearing of jewelry, such as police officers or electrical workers. In some jurisdictions, those in the food service industry may be required to remove all jewelry while handling ready-to-eat food, including wedding rings, unless they are simple, smooth rings. Physicians known to prefer smooth, simple designs, some may even autoclave their rings on a regular basis. Many times these people say they wear a "ring around their heart" not around their finger. Some will wear it on a chain around their neck to compensate for the inability to wear it on a finger.

Emeralds

Emeralds, like all colored gemstones, are graded using four basic parameters – the four Cs of Gemstones: Color, Cut, Clarity and Crystal. The last C, crystal is a synonym that begins with C for transparency or what gemologists call diaphaneity. Before the 20th century, jewelers used the term water as in a gem of the finest water to express the combination of two qualities, color and crystal. Normally, in the grading of colored gemstones, color is by far the most important criterion. However, in the grading of emerald, crystal considered a close second. Both are necessary conditions. A fine emerald must possess not only a pure verdant green hue as described below, but also a high degree of transparency considered a top gem. In the 1960s, the American jewelry industry changed the definition of emerald to include the green vanadium-bearing beryl as emerald. As a result, vanadium emeralds purchased as emeralds in the United States recognized as such in the UK and Europe. In America, the distinction between traditional emeralds and the new vanadium kind reflected in the use of terms such as Colombian Emerald. Scientifically speaking, color divided into three components: hue, saturation and tone. Yellow and blue, the hues found adjacent to green on the spectral color wheel, are the normal secondary hues found in emerald. Emeralds occur in hues ranging from yellow-green to blue-green. The primary hue must be green. Only gems that are medium to dark in tone considered emerald. Light-toned gems known by the species name, green beryl. In addition, the hue must be bright (vivid). Gray is the normal saturation modifier or mask found in emerald. A grayish green hue is a dull green. Emerald tends to have numerous inclusions and surface breaking fissures. Emerald graded by eye. Thus, if an emerald has no visible inclusions to the eye it considered flawless. Stones that lack surface breaking fissures are extremely rare and therefore almost all emeralds are treated, oiled, to enhance the apparent clarity. Eye-clean stones of a vivid primary green hue with no more than 15% of any secondary hue or combination of a medium-dark tone command the highest prices.6 This relative crystal non-uniformity makes emeralds more likely than other gemstones to be cut into cabochons, rather than faceted shapes.