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GOLD
Gold is a beautiful and imperishable metal. It was one of the first metals to be mined
because it commonly occurs in its native form (100% Pure)Pure (100%) gold is too soft, and it is usually mixed with other
metals (gold alloys) to make it stronger and more usable for jewelry.
The metals that are mixed with pure gold for strength
can also modify the color of gold resulting in different shades of yellow, white, and pink.
KARATS - Indicate the
amount of pure gold in the metal. Abbreviation: kt
37.5% 41.7% 58.5% 75% 100%
9 kt 10 kt 14 kt 18 kt 24 kt
375
417 585 750 999
PRICE - The following are some of the factors that determine the value of a gold
jewelry piece.
Weight: gold is sold by weight - grams(gr) or pennyweights(dwt), the heavier the piece, the higher the gold content,
therefore it is more expensive.
Design: designer jewelry is more expensive, especially if it is a one of a kind piece.
Finish: special finishes to the metal such as matte, or sand-blasted finish add to the cost of the gold jewelry piece.
PLATINUM
The platinum group metals (PGM), comprise six closely related metals: Platinum, Palladium,
Rhodium, Ruthenium, Iridium and Osmium.
Platinum has a deep luster and a rich, white color. It is rarer, heavier and
denser than all precious metals and considered to be more valuable than gold.
Platinum is often used to set the most
valuable gems to produce the finest jewelry because it holds gemstones most securely and it neutral color enhances the brilliance
and depth of diamonds and precious stones.
In the United States platinum is usually marked: PT or PLAT
In Europe,
it is marked: 950 or PT950
SILVER
Silver is the most reflective and affordable of the precious metals.
Sterling silver is the standard of quality for articles containing 92.5% silver and 7.5% copper.
Vermeil is
a gold plated sterling silver.
MARKS - percentage of pure silver
General -Sterling Silver
American - 925
European - 935
French - 800
Russian - 88 or 84
Platinum Group Metals (PGM):
Palladium (Pd)
It
is a relatively rare and soft, silvery white metal. When used in jewelry, it is alloyed with gold to create white gold.
It
is also used to make setting.
Rhodium (Rh)
It is a brilliant silvery white metal that is used as a plating agent
on platinum and white gold to create a white very hard coating.
Ruthenium (Ru)
It is a grayish-white metal that
has a high resistance to wear and is used in the manufacture of jewelry, porcelain, etc.
Iridium (Ir)
It is a
white, brittle and extremely hard metal. The alloy, which contains about 10 percent iridium and 90% platinum, is much harder
than pure platinum. Alloys containing larger percentages of iridium are used in making precision and standard instruments,
surgical tools, pen points.
Osmium (Os)
It is a bluish-white, brittle metal. Osmium and platinum alloy is used
for standard weights and measures.
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