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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 jewellery usually includes gold, white gold, platinum,
palladium, 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 England the number is 9K 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.[citation needed]
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.
Other commonly used materials include glass, such as fused-glass
or enamel; wood, often carved or turned; shells and other
natural animal substances such as bone and ivory; natural clay;
polymer clay; and even plastics. However, any inclusion of lead
or lead solder will cause an English Assay office (the building
which gives English jewellery its 'stamp of approval, the
Hallmark) to destroy the piece. [citation needed]
Contemporary bead embroidery design.
Contemporary bead embroidery design.
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, and belts. 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.
Advanced glass and glass beadmaking techniques by Murano and
Venetian glassmasters developed crystalline glass, enameled
glass (smalto), glass with threads of gold (goldstone),
multicoloured glass (millefiori), milk-glass (lattimo) and
imitation gemstones made of glass.[citation needed] As early as
the 13th century, Murano glass and Murano beads were
popular.[citation needed]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
A selection of diamonds.
Diamonds, long considered the most prized of gemstones, were
first mined in India.[7] Pliny may have mentioned them, although
there is some debate as to the exact nature of the stone he
referred to as Adamas;[8] 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
Although diamonds are considered the most prized of all
gemstones, many other precious stones are used for jewellery.
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
For platinum, gold, and silver jewellery there are many
different techniques to create different finishes. The most
common however 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. |
