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creating jewelry, 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 jewelry - bronze,
for example, was common in Roman times. Modern
fine jewelry usually includes gold, white gold,
platinum, palladium, titanium or silver. Most
American and European gold jewelry 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 jewelry 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 jewelry 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 jewelry is usually sterling silver,
or 92.5% fine silver. In costume jewelry,
stainless steel findings are sometimes used.
Bead embroidery design.
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. Hemp and other twines
have been used as well to create jewelry that
has more of a natural feel. However, any inclusion
of lead or lead solder will cause an English Assay
office (the building which gives English jewelry
its stamp of approval, the Hallmark) to destroy
the piece. Beads are frequently used in jewelry.
These may be made of glass, gemstones, metal,
wood, shells, clay and polymer clay. Beaded jewelry
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 jewelry. 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 jewelry
making. Beading, or beadwork, is also very popular
in many African cultures.
Advanced glass and glass bead making techniques
by Murano and Venetian glass masters developed
crystalline glass, enameled glass (smalto), glass
with threads of gold (goldstone), multicolored
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 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). |