What is the difference between 9 carat and 18 carat gold?

18 carat gold jewellery is made up of 750 parts pure gold out of 1000 parts, the remaining 250 parts being made up of other metals, mainly copper and silver. 9 carat gold jewellery is made up of 375 parts pure gold out of 1000 parts, the remaining 625 parts is made up of other metals such as silver, nickel, palladium and zinc. So 9 carat gold is just over 1/3rd gold content, whereas, 18 carat gold has ¾ pure gold content. So for example, say you have in front of you a mobile phone, if your phone was made of 9ct Gold, one third of the phone would be pure 24ct gold, the remaining two thirds would be made up of alloys (silver, nickel, palladium & zinc) If your mobile phone was made of 18ct Gold, two thirds of the phone would be pure 24ct gold with only one third being made of alloys - hence the difference in price between the two items.

18 carat gold is practically completely resistant to chemical attack in normal use, whereas 9 carat gold is much less resistant. Be aware that 9 carat gold will tarnish, go dull, bleach some fabrics and sometimes turn black from chemicals in the atmosphere, perspiration and household cleaners. That is why sometimes some people have an allergic reaction to wearing 9 carat gold, leaving black or green marks on the skin. This is a chemical reaction to the metal alloys, not the gold, usually the nickel in 9 carat gold reacting with the skin. Nickel is the most common cause of dermatitis through allergic reactions when in contact with the skin.

Nickel is not present in 18 carat gold. Our 750jewellery 18 carat gold items are nickel safe and our policy is to use only ’white gold’ alloys containing palladium.

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Just arrived in stock - Linda Macdonald Jewellery

Linda Macdonald necklaces http://bit.ly/bBV1LD

Linda Macdonald earrings http://bit.ly/cMtbsw

Linda Macdonald bangles http://bit.ly/b2K6Ss

Linda Macdonald rings & stack rings http://bit.ly/bjjoGW

Unlike gold, silver is assayed using a

process known as “potentiometric titration”.

A sample will be scraped from the item

to be assayed which weighs between

50 and 250 milligrams. The sample is

then weighed using a highly accurate

balance and dissolved in nitric acid.

In order to determine the silver content,

potassium chloride is added to the

sample and the electrical conductivity

of the solution is tested until the point

that the “titration” is complete and all of

the silver has become silver chloride. The

amount of potassium chloride needed to

get to this point indicates the amount

of silver that was in the original sample.   www.750jewellery.com

Turquoise is the big colour for 2010 - Claudia Bradby earrings & necklet http://bit.ly/ayKtpM http://bit.ly/aXojiT

Where did Sky News presenter Sarah Hughes get her necklace from?

http://bit.ly/aN010E

Palladium is one of the platinum group metals but is considered a precious metal in its own right. Palladium is naturally white which means that there is no need for rhodium plating. Palladium is more precious than silver. It is less dense than platinum, being nearly half the weight, so larger necklaces and bracelets can be made, capable of bearing larger gemstones with minimal gain in overall weight. For the same reason, palladium is considered to be a good choice for earrings although unlike platinum it is not hypoallergenic. It is often recommended as a good alternative to 9Kt white gold for male bridal consumers due to it never needing re-plating.

(with thanks to CIJBO)

New arrivals from Nina B Jewellery - Silver charms & glass beads (compatible with Pandora, Chamillia & Troll bracelets) http://bit.ly/beiSs3

New arrivals this week Nina B glass bead & silver charms - compatible with Pandora & Troll http://bit.ly/beiSs3

New silver & pearl jewellery arrivals this week.

New designers - Claudia Bradby and Nina B - new arrivals this week. Silver bracelets, silver & pearl necklaces, silver earrings.

New lovely silver bracelet arrivals this week http://bit.ly/9Eks55

New lovely silver and pearl necklaces http://bit.ly/bTq1mG

New lovely silver earrings http://bit.ly/docinY

New lovely glass and sterling silver beads and charms added - all fit Pandora and Troll bracelets.

http://www.750jewellery.com/products/httpwww750jewellerycomproductscharmshtml.html