General Info

In creating jewellery, gemstones, coins, or other precious items are often used, and they are typically set into precious metals. Alloys of nearly every metal known have been encountered in jewellery - bronze, for example, was common in Roman times. Modern fine jewellery usually includes gold, white gold, platinum, palladium, titanium or silver. Most American and European gold jewellery is made of an alloy of gold, the purity of which is stated in karats, indicated by a number followed by the letter K. American gold jewellery must be of at least 10K purity (41.7% pure gold), (though in the UK the number is 9K (37.5% pure gold) and is typically found up to 18K (75% pure gold). Higher purity levels are less common with alloys at 22 K (91.6% pure gold), and 24 K (99.9% pure gold) being considered too soft for jewellery use in America and Europe. These high purity alloys, however, are widely used across Asia, the Middle East and Africa. Platinum alloys range from 900 (90% pure) to 950 (95.0% pure). The silver used in jewellery is usually sterling silver, or 92.5% fine silver. In costume jewellery, stainless steel findings are sometimes used.

 

Beads are frequently used in jewellery. These may be made of glass, gemstones, metal, wood, shells, clay and polymer clay. Beaded jewellery commonly encompasses necklaces, bracelets, earrings, belts and rings. Beads may be large or small, the smallest type of beads used are known as seed beads, these are the beads used for the "woven" style of beaded jewellery. Another use of seed beads is an embroidery technique where seed beads are sewn onto fabric backings to create broad collar neck pieces and beaded bracelets. Bead embroidery, a popular type of handwork during the Victorian era is enjoying a renaissance in modern jewellery making. Beading, or beadwork, is also very popular in many African cultures.
Advanced glass and glass beadmaking techniques by Murano and Venetian glassmasters developed crystalline glass, enamelled glass (smalto), glass with threads of gold (goldstone), multicoloured glass (millefiori), milk-glass (lattimo) and imitation gemstones made of glass. As early as the 13th century, Murano glass and Murano beads were popular
Silversmiths, goldsmiths, and lapidaries methods include forging, casting, soldering or welding, cutting, carving and "cold-joining" (using adhesives, staples and rivets to assemble parts).^[6]

Diamonds

Diamonds.

Main article: Diamond

Diamonds were first mined in India. Pliny may have mentioned them, although there is some debate as to the exact nature of the stone he referred to as Adamas; In 2005, Australia, Botswana, Russia and Canada ranked among the primary sources of gemstone diamond production.
The British crown jewels contain the Cullinan Diamond, part of the largest gem-quality rough diamond ever found (1905), at 3,106.75 carats (621.35 g).
Now popular in engagement rings, this usage dates back to the marriage of Maximilian I to Mary of Burgundy in 1477.

Other gemstones

Main article: Gemstone

Many precious and semiprecious stones are used for jewellery. Among them are:

Amber

Amber, an ancient organic gemstone, is composed of tree resin that has hardened over time. The stone must be at least 1 million years old to be classified as amber, and some amber can be up to 120 million years old.

Amethyst

Amethyst has historically been the most prized gemstone in the quartz family. It is treasured for its purple hue, which can range in tone from light to dark.

Spanish emerald and gold pendant at Victoria and Albert Museum.

Emerald

Emeralds are one of the three main precious gemstones (along with rubies and sapphires) and are known for their fine green to bluish green colour. They have been treasured throughout history, and some historians report that the Egyptians mined emerald as early as 3500 BC.

Jade

Jade is most commonly associated with the colour green, but can come in a number of other colours as well. Jade is closely linked to Asian culture, history, and tradition, and is sometimes referred to as the stone of heaven.

Jasper

Jasper is a gemstone of the chalcedony family that comes in a variety of colours. Often, jasper will feature unique and interesting patterns within the coloured stone. Picture jasper is a type of jasper known for the colours (often beiges and browns) and swirls in the stone’s pattern.

Quartz

Quartz refers to a family of crystalline gemstones of various colours and sizes. Among the well-known types of quartz are rose quartz (which has a delicate pink colour), and smoky quartz (which comes in a variety of shades of translucent brown). A number of other gemstones, like Amethyst and Citrine, are also part of the quartz family. Rutilated quartz is a popular type of quartz containing needle-like inclusions.

Ruby

Rubies are known for their intense red colour, and are among the most highly valued precious gemstones. Rubies have been treasured for millennia. In Sanskrit, the word for ruby is ratnaraj, meaning king of precious stones.

Sapphire

The most popular form of sapphire is blue sapphire, which is known for its medium to deep blue colour and strong saturation. Fancy coloured sapphires in various colours are also available. In the United States, blue sapphire tends to be the most popular and most affordable of the three major precious gemstones (emerald, ruby and sapphire).

Turquoise

Turquoise is found in only a few places on earth, and the world’s largest turquoise producing region is the southwest United States. Turquoise is prized for its attractive colour, most often an intense medium blue or a greenish blue, and its ancient heritage. Turquoise is used in a great variety of jewellery styles. It is perhaps most closely associated with southwest and Native American jewellery, but it is also used in many sleek, modern styles. Some turquoise contains a matrix of dark brown markings, which provides an interesting contrast to the gemstone’s bright blue colour.

Some gemstones (like pearls, coral, and amber) are classified as organic, meaning that they are produced by living organisms. Others are inorganic, meaning that they are generally composed of and arise from minerals.
Some gems, for example, amethyst, have become less valued as methods of extracting and importing them have progressed. Some man-made gems can serve in place of natural gems, an example is the cubic zirconia, used in place of the diamond.

Metal finishes

An example of gold plated jewellery

For platinum, gold, and silver jewellery there are many techniques to create finishes. The most common are high-polish, satin/matte, brushed, and hammered. High-polished jewellery is by far the most common and gives the metal the highly-reflective and shiny look. Satin, or matte finish reduces the shine and reflection of the jewellery and is commonly used to accentuate gemstones such as diamonds. Brushed finishes give the jewellery a textured look, and are created by brushing a material (similar to sandpaper) against the metal, leaving 'brush strokes'. Hammered finishes are typically created by using a soft, rounded hammer and hammering the jewellery to give it a wavy texture.
Some jewellery is plated to give it a shiny, reflective look or to achieve a desired colour. Sterling silver jewellery may be plated with a thin layer of 0.999 fine silver (a process known as flashing) or may be plated with rhodium or gold. Base metal costume jewellery may also be plated with silver, gold, or rhodium for a more attractive finish.

what are jewellries?

Jewellery (pronounced /ˈdʒuːəlri/ or /ˈdʒuːələri/) or jewelry (see American and British English spelling differences) signifies items of personal adornment, such as necklaces, rings, brooches, earringsbracelets. Jewellery may be made from any material, such as gemstones, precious metals or shells, besides other materials, depending on cultural differences and availability of materials. Jewellery may be appreciated because of geometric or other patterns, or meaningful symbols. (Items such as belts and handbags etc. are considered to be accessories rather than jewellery.) and

The word jewellery is derived from the word jewel, which was Anglicised from the Old French "jouel" circa the 13th century.^[1] Further tracing leads back to the Latin word "jocale", meaning plaything. Jewellery is one of the oldest forms of body adornment; recently found 100,000 year-old beads made from Nassarius shells, are thought to be the oldest known jewellery.^[2]

Jewellery is sometimes seen as wealth storage or functionally as holding a garment or hair together. It has from very early times also been regarded as a form of personal adornment. The first pieces of jewellery were made from natural materials, such as bone, animal teeth, shell, wood and carved stone. More exotic jewellery was probably made for wealthy people or as indications of social status. In some cases people were buried with their jewellery.

Jewelery has been made to adorn nearly every body part, from hairpins to toe rings and many more types of jewellery. While high-quality jewellery is made with gemstones and precious metals, such as silver or gold, there is also a growing demand for art jewellery where design and creativity is prized above material value. In addition, there is the less costly costume jewellery, made from lower value materials and mass-produced. Other variations include wire sculpture (wrap) jewellery, using anything from base metal wire with rock tumbled stone to precious metals and precious gemstones.

Diamante

Am gasit pe net, cautand o clasificare pentru cei ce vor sa isi cumpere diamante, o mica clasificare a descrierii diamantelor. Sper sa fie utila:

Classification of natural diamond

Type Ia diamond: Contains nitrogen as an impurity in fairly substantial amounts (of the order of 0.1%), and which appears to have segregated into small aggregates. Also contains platelets, associated with the nitrogen impurity, the exact structure of which is not known. Most natural diamonds are of this type. Type Ib diamond: Also contains nitrogen as an impurity but in dispersed substitutional form. Almost all synthetic diamonds are of this type.
Type IIa diamond: effectively free of nitrogen impurity. Very rare in nature, these diamonds have enhanced optical and thermal properties.
Type IIb diamond: A very pure type of diamond which has semiconducting properties: generally blue in colour. Extremely rare in nature.